This page shows what was measured, who it was measured in, and what that does not settle.
What Dutasteride does in the body
An enlarged prostate, where the aim is to shrink the gland rather than relax it
The prostate does not respond to testosterone directly. It converts testosterone into a stronger hormone, dihydrotestosterone, using an enzyme that sits inside prostate cells, and it is that stronger hormone which keeps the gland growing. Dutasteride jams both versions of that enzyme, so dihydrotestosterone in the blood falls by around 90% and the androgen-dependent part of the gland gradually shrinks. Because it works by removing a growth signal rather than by relaxing muscle, nothing happens for months.
What happened in people
Serum dihydrotestosterone fell 90.2% and total prostate volume 25.7% at 24 months in 4,325 randomised men
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The recorded finding that sits closest to something a person would notice. Written into the record, not signed off, and it carries no population or interval.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
The limit that matters most
That preventing biopsy-detected cancer prevents prostate cancer death — REDUCE had no mortality endpoint and reported no survival result
Where it acts
Prostate epithelium and stroma, with the type 1 isoenzyme also inhibited in skin and liver
Kind of result
A number that stands in for health
Supervision
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
What the registries record it as
The substance registry classes this as chemical.
FDA substance registry · O0J6XJN02I · read 2026-08-29
Where each sentence above came from
No recorded sentence describes the change this makes in a way that stands on its own. The page opens with what it is taken for instead, and the recorded explanation follows below.
Shown as the opening line on this page.
A limit recorded against this substance. Not signed off as a reviewed claim.
The four opening statements run to 113 words.
Words this page uses
Four words worth knowing first
Chosen from what this page shows, with each one explained before the word it depends on.
Stand-in result
A stand-in result is a number measured because the real result takes too long.
A picture of it, and where the picture fails
It is like judging a journey by the speedometer rather than by arriving.
Where that stops being true. Speed does predict arrival. Many stand-in results do not predict the real one.
What people get wrong. A stand-in result is often reported as the result itself.
A surrogate endpoint substituted for a clinical endpoint, valid only where the substitution has been shown to hold.
Randomisation
Randomisation means chance decides who gets which treatment.
A picture of it, and where the picture fails
It is like a coin toss deciding the groups.
Where that stops being true. A coin toss is fair once. Fairness here comes from doing it for everyone.
What people get wrong. It is thought to make groups identical. It makes them similar on average, including on things nobody measured.
Allocation of participants to arms by a chance process, so that unmeasured factors are balanced in expectation.
Absolute difference
An absolute difference is how many more people in a hundred were affected.
A picture of it, and where the picture fails
It is like counting heads in two rooms of a hundred.
Where that stops being true. Heads are easy to count. Study results carry a margin of error too.
What people get wrong. It is confused with a percentage change, which can look far larger.
The arithmetic difference in event rates between arms.
Confidence interval
A confidence interval is the range the true answer is likely to sit in.
A picture of it, and where the picture fails
It is like a weather forecast giving a range rather than one number.
Where that stops being true. A forecast range covers tomorrow. This one covers what the study could resolve.
What people get wrong. The middle number is read as the answer. A range crossing zero means no change is still possible.
An interval estimate that would contain the true parameter in a stated proportion of repeated studies.
What happened in people◇Read from sources, not yet reviewed
What was measured, goal by goal
One row for each goal a registered study measured something for. One column for each kind of thing that could be measured.
Registered studies list 40 outcome measures that RNAWiki could read. A registered study says what someone planned to measure. It does not say what they found. 0 of the matched studies tested this substance, and 0 posted a result.
There is no single score. A strong test result and a weak life result are different facts.
Goals down the side, kinds of measurement across the top. Each cell says what kind of thing was registered, not what was found.
Goal
Life outcome
What a body can do
How a person feels
A test result
A step in the body
Harms
How long
Who was studied
Fertility and sexual health
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
∅Nothing in the sources checkedNo registered study lists a symptom measure for this goal.
△Only a number moved3 registered test measure.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Blood sugar
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
∅Nothing in the sources checkedNo registered study lists a symptom measure for this goal.
△Only a number moved2 registered test measure.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Cholesterol
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
∅Nothing in the sources checkedNo registered study lists a symptom measure for this goal.
∅Nothing in the sources checkedNo registered study lists a test result for this goal.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Which registered measures put each goal on this table
P < 0.001 for symptom score, prostate volume, dihydrotestosterone and maximum flow rate; 57% relative risk reduction for acute urinary retention and 48% for surgery
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral soft gelatin capsule, taken once daily
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
Incidence of biopsy-detectable prostate cancer at years 2 and 4
✓ The study showed what it set out to show
Who was studied
REDUCE (NCT00056407)
How many people
8231
Study design
Phase 3 randomised double-blind placebo-controlled, 4 years
Compared against
A dummy treatment
Kind of result
A number that stands in for health
What was found
P < 0.001 for a 22.8% relative risk reduction (95% CI 15.2 to 29.8) in biopsy-detected prostate cancer
Repeated elsewhere
Partially Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Gleason 8-10 tumours in years 3 and 4: 12 on dutasteride against 1 on placebo (p=0.003). Cardiac failure composite 0.7% against 0.4% (p=0.03). No prostate-cancer-prevention indication was granted and the high-grade finding is on the label as a warning.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral soft gelatin capsule, taken once daily
Interval reported. 95% CI 15
Written into the record, not signed off as a reviewed claim.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
Relative risk of acute urinary retention or BPH-related surgery with combination therapy versus each monotherapy
✓ The study showed what it set out to show
Who was studied
CombAT (NCT00090103)
How many people
4844
Study design
Phase 3 randomised double-blind, 4 years
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Combination was significantly superior to tamsulosin monotherapy but not to dutasteride monotherapy for acute urinary retention or BPH-related surgery
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. The published report notes an imbalance in the composite term of cardiac failure across the three arms, the second such observation in a large dutasteride trial.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral soft gelatin capsule, taken once daily
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
Change in total prostate volume, dutasteride versus finasteride
✗ The study did not show it
Who was studied
EPICS (Enlarged Prostate International Comparator Study)
How many people
1630
Study design
Randomised double-blind active comparator, 48 weeks plus open-label extension
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
No significant difference between dutasteride and finasteride in prostate volume reduction, AUA Symptom Index or maximum urinary flow rate
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. `endpoint met: false` here records that the superiority hypothesis behind dual isoenzyme inhibition was not confirmed, not that the drug failed to shrink the prostate.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral soft gelatin capsule, taken once daily
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
RNAWiki holds 4 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What happened in people◇Read from sources, not yet reviewed
How close this is to real life
The top step is something a person would feel or care about. The bottom is a guess from software. Filled steps are where evidence exists for this substance.
■Living longer, or avoiding a major eventEvidence recorded. Death, a heart attack, a stroke, a hospital stay.2 registered measures of this kind. No reviewed result.
□What a body can do day to dayNo evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
□Measured performanceNo evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
□Symptoms and quality of lifeNo evidence recorded. Pain, tiredness, mood, sleep, as the person rated it.No registered study measures this.
■A number that stands in for healthEvidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.9 registered measures of this kind.
■A step measured inside a personEvidence recorded. Something measured in human tissue or human cells.1 registered measure inside human tissue.
□AnimalsNo evidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.No animal record is stored.
■Cells in a dishEvidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
□A guess from softwareNo evidence recorded. Nobody measured it. RNAWiki never publishes one as a finding.RNAWiki stores no prediction for this record. Software can suggest a link. RNAWiki does not publish one as a finding.
Higher on these steps means closer to something a person would feel. It does not mean better done.
What it changes in the body◇Read from sources, not yet reviewed
The path through the body
From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.
Start
Dutasteride
What a person takes: Oral soft gelatin capsule, taken once daily.
The measurement behind this step
Swallowed whole. The capsules are not to be opened, chewed or handled by women who are or may be pregnant, because the contents can be absorbed through skin and 5-alpha-reductase inhibitors interfere with development of the external genitalia of a male fetus.
Getting in
Taken as a capsule, and it accumulates for months
This is not a drug that reaches its working level in a day. Because the body clears it so slowly, the amount in the blood keeps rising for months before it settles.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Oral soft gelatin capsule, absorbed with a terminal elimination half-life of approximately five weeks at steady state. Extensively protein-bound, metabolised by CYP3A4. Serum concentrations remain detectable above 0.1 ng/mL for four to six months after the last dose, which is the pharmacokinetic basis for the six-month blood donation deferral.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
Reaching the cell
It crosses into the cell, because that is where the enzyme is
Unlike a drug that works on the outside of a cell, this one has to get inside. The enzyme it blocks sits on internal membranes within prostate cells.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
Dutasteride is a lipophilic 4-azasteroid and crosses the plasma membrane by passive diffusion. 5-alpha-reductase is an integral membrane protein of the endoplasmic reticulum and nuclear membrane, with the type 2 isoenzyme predominating in prostate and the type 1 isoenzyme also present in skin and liver.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
What it acts on
It locks onto both versions of the enzyme and does not let go
The drug binds the enzyme in a way that is very hard to reverse, and it does this to both forms of the enzyme rather than just one. That grip is why the effect lasts so long.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
The label describes a competitive and specific inhibition of both type 1 and type 2 5-alpha-reductase, forming a stable enzyme complex. Finasteride is largely type 2 selective. The dissociation of that complex is slow enough that the pharmacodynamic effect outlasts plasma clearance.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
The change it makes
Testosterone stops being converted, and dihydrotestosterone collapses
The step that turns testosterone into the stronger prostate hormone stops happening. Levels of that stronger hormone in the blood fall by around ninety per cent.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Serum dihydrotestosterone fell 90.2% at 24 months in the pooled ARIA trials, median -93.7% (p<0.001). Testosterone is not removed and typically rises modestly. Intraprostatic dihydrotestosterone falls further than serum, since both isoenzymes are inhibited within the gland itself.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
What that does for a person
Androgen-dependent tissue involutes, and the outcomes follow
Deprived of its growth signal, part of the gland shrinks over months. That translated into fewer men unable to pass urine and fewer operations.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Total prostate volume fell 25.7% and transition zone volume 20.4% at 24 months. Symptom score improved 4.5 points and maximum flow rate 2.2 mL/sec. Acute urinary retention risk fell 57% and BPH-related surgery 48% against placebo. Serum PSA falls by approximately 50%, which is a consequence of the same epithelial involution and complicates cancer surveillance.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
No suggested links are held for this record, so nothing is hidden from this path.
What we know
The record describes 5 steps from taking it to an effect in a person.
How we know it
Each step names the study behind it in the technical detail beside it.
What this does not prove
A change inside the body is a reason to look. It is not a result in a person.
Why it matters
A reader can see exactly where the chain stops being measured in people.
What we still do not know
No reviewed claim binds any of these steps to a named population.
What it would be like to take◇Read from sources, not yet reviewed
Felt, measured, or meaningful
Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.
Felt
Things a person could notice without a test.
No registered study measured anything of this kind.
Measured
Things only a test, a scale or a device shows.
biopsy detectable prostate cancer at years 2 and 4
insulin resistance
elevations in serum testosterone
growth hormone concentration after injections
testosterone concentration
dihydrotestosterone concentration
plasma lapatinib levels
insulin sensitivity
serum psa
sperm concentration
Meaningful
Things that change how a life goes, not only a number.
time to disease progression
radiographic progression free survival rate
A registered study says what someone planned to measure. It does not say what they found. A number moving is not the same as a life going better. The two are shown apart here.
Felt, but not shown to help. A person notices a change. No study showed it leads anywhere good.
Measured, but not felt. A number moves. The person notices nothing. Both can be true.
Measured, but not shown to matter. A number moves in the good direction. Nobody showed that lives went better.
Matters, but takes years. The result that counts may take longer than anyone would keep watching.
Names that fit none of the three (28)
bone metabolism
lipid profile
toxicity
prostate specific antigen
fat free mass measured by dexa scanning
total prostate volume
lapatinib maximum tolerated dose
lapatinib dose limiting toxicity
intratesticular testosterone level
intratesticular dihydrotestosterone level
intratesticular androstenedione level
change number of standard drinks per week
an adverse event
androgen receptor related mutations
pathologic complete response rate
bioavailability
heavy drinking days per week
drinks per week
no heavy drinking days
area under curve of tadalafil
These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.
What it would be like to take◇Read from sources, not yet reviewed
How long anything takes
Nine different lengths of time that get confused with each other. None of them is worked out from another.
Before anything is noticed.RNAWiki does not store this separately, and never works it out from another figure on this page.
Before a test result moves.RNAWiki does not store this separately, and never works it out from another figure on this page.
Before performance moves.RNAWiki does not store this separately, and never works it out from another figure on this page.
How long the result was watched.No finished study window is recorded for a study that tested this substance.
How long people took it.How long people actually took it is not stored. The study window is not the same thing.
How long people were followed.Follow-up length is not stored separately. It is never read off the study window, which would be a different thing.
How fast the body clears it. 170 hours hours
Read from the label, which states: “In this single-dose trial, dutasteride half-life increased with age (approximately 170 hours in men aged 20 to 49 years, approximately 260 hours in men aged 50 to 69 years, and approximately 300 hours in men older than 70 years).”
How long effects linger.RNAWiki does not store this separately, and never works it out from another figure on this page.
Beyond the studies. Nothing is recorded about the long term.
The longest finished study sets the edge of what anyone measured.
A study window is not how long people took it, and neither is how long they were followed. Where RNAWiki holds only one of the three, it shows one.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
Men with an enlarged prostate, usually 30 cm3 or more, since gland size predicts who benefits. It is also used off-label for male pattern hair loss, at a dose and for a duration no outcome trial in this file covers.
Who is missing from the studies
Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What the label states about particular groups
On pediatric, the label states: “Safety and effectiveness in pediatric patients have not been established.”
US prescribing information · 2ee1eef5-8ec7-46c1-b4fa-13184915448f · read 2026-08-30
On older people, the label states: “Of 2,167 male subjects treated with dutasteride capsules in 3 clinical trials, 60% were aged 65 years and older and 15% were aged 75 years and older.”
US prescribing information · 2ee1eef5-8ec7-46c1-b4fa-13184915448f · read 2026-08-30
On people who are pregnant, the label states: “Risk Summary Dutasteride is contraindicated for use in pregnancy because it may cause harm to the male fetus [see Contraindications (4) ].”
US prescribing information · 2ee1eef5-8ec7-46c1-b4fa-13184915448f · read 2026-08-30
On people who are breastfeeding, the label states: “Risk Summary Dutasteride is not indicated for use in women.”
US prescribing information · 2ee1eef5-8ec7-46c1-b4fa-13184915448f · read 2026-08-30
On people with reduced liver function, the label states: “The effect of hepatic impairment on dutasteride pharmacokinetics has not been studied.”
US prescribing information · 2ee1eef5-8ec7-46c1-b4fa-13184915448f · read 2026-08-30
On people with reduced kidney function, the label states: “No dose adjustment is necessary for dutasteride capsules in patients with renal impairment [see Clinical Pharmacology (12.3)].”
US prescribing information · 2ee1eef5-8ec7-46c1-b4fa-13184915448f · read 2026-08-30
Where the result stopped carrying
The prostate-cancer-prevention indication. The trial met its registered endpoint and the label carries a high-grade cancer warning instead of a prevention claim.
The superiority case for dual isoenzyme inhibition, which was the commercial rationale for developing a second 5-alpha-reductase inhibitor
Any attempt to use PSA normally in men on this drug, since the drug halves the marker it would be read against
This is a scope explorer, not a diagnosis engine.
It shows who was studied so you can see whether people similar to you were included.
RNAWiki cannot tell whether a study fits you. It can show who was in it.
What it would be like to take◇Read from sources, not yet reviewed
Why it might seem to do nothing
A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.
It was studied for a different goal
The studies measured something else entirely.
On this record: Some registered studies measured things that match no goal on this page.
It was studied in different people
The people in the studies were not much like the reader.
On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
The evidence may simply be wrong
Small early studies often do not hold up.
On this record: RNAWiki has not yet published a reviewed conclusion for this use.
Other reasons RNAWiki checked and found nothing for (10)
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
Prescription only
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Oral soft gelatin capsule, taken once daily
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form and route recorded on this substance.
No source is stored against this line.
Who oversees it
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Suppression classes recorded: S3.
No source is stored against this line.
What is in the pack
Swallowed whole.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on how this is sold. The rest of the recorded wording: The capsules are not to be opened, chewed or handled by women who are or may be pregnant, because the contents can be absorbed through skin and 5-alpha-reductase inhibitors interfere with development of the external genitalia of a male fetus.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take◇Read from sources, not yet reviewed
What can go wrong
Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.
·Worth asking a clinician aboutWritten into the record from the studies named on this page
The commonest adverse reactions are impotence, decreased libido, breast disorders including enlargement and tenderness, and ejaculation disorders. Warnings and Precautions cover increased incidence of Gleason 8-10 prostate cancer, the effect on PSA and prostate cancer detection, exposure of women and blood donation deferral for six months after the last dose. Serum PSA falls by approximately 50%, and any confirmed rise from the on-treatment nadir warrants evaluation even within the ordinary reference range.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
REDUCE — Reduction by Dutasteride of Prostate Cancer Events, 4-year randomised placebo-controlled trial (NCT00056407) · a recorded source, not a stored snapshot
Reports sent to a regulator
These are reports people sent to a regulator. They do not show the medicine caused the reaction.
Nobody counted how many people took the medicine and reported nothing.
The same event can be reported more than once, and many reports are incomplete.
News coverage, lawsuits and new warnings change how often people report.
A count is not a rate and not a risk.
Dutasteride appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 433 reaction mentions were counted. One report can name several reactions.
open-targets-adr · recorded 2026-06-24 · a recorded source, not a stored snapshot
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear◇Read from sources, not yet reviewed
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
Oral soft gelatin capsule, taken once daily
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form used in the studies cited on this page.
No source is stored against this line.
What is sold
A recorded note compares this form with the others that are sold. It is kept below, word for word.
§ A fixed RNAWiki sentence
Where this came from
Wording RNAWiki always uses, not a finding about this substance.
The recorded note, unchanged: The capsules are not to be opened, chewed or handled by women who are or may be pregnant, because the contents can be absorbed through skin and 5-alpha-reductase inhibitors interfere with development of the external genitalia of a male fetus.
No source is stored against this line.
What is recorded as being sold
55 products list this as an active ingredient in the United States drug directory. 50 of them contain it and nothing else.
FDA National Drug Code directory · 11014-0340 · read 2026-08-29
They are sold as capsule, capsule, gelatin coated, capsule, liquid filled and powder, taken oral.
FDA National Drug Code directory · 11014-0340 · read 2026-08-29
The regulator's established pharmacologic class for it is 5-alpha reductase inhibitor [epc] and 5-alpha reductase inhibitors [moa].
FDA National Drug Code directory · 11014-0340 · read 2026-08-29
24 published labels name it as an active ingredient. 20 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · 2ee1eef5-8ec7-46c1-b4fa-13184915448f · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · 2ee1eef5-8ec7-46c1-b4fa-13184915448f · read 2026-08-29
Dutasteride is oral at 3 DOSAGE FORMS AND STRENGTHS 0.5-mg, opaque, yellow, oblong shape capsules imprinted with “PC23” in red ink. 0.5-mg capsules ( 3 ), recorded as fda label in effect 2025-01-08 in the United States.
US prescribing information · 2ee1eef5-8ec7-46c1-b4fa-13184915448f · read 2026-08-30
Recorded price in US: 0.1606 USD per one unit as the pricing file counts it — a tablet, capsule, patch or single item, across 7 priced products whose strengths and pack forms differ, as of 2026-08-26, paid by retail pharmacies buying the product, as surveyed by the Centers for Medicare & Medicaid Services. It is not a list price, an insurance price, or what anyone pays at a counter..
Recorded source · 2026-08-26 · read 2026-08-28
Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.
What it would be like to take◇Read from sources, not yet reviewed
What you could measure
This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.
Self-experiment planning is not offered for a prescription or clinician-supervised medicine. The questions below are for a clinician or pharmacist.
Questions worth asking
Which of the trials of Dutasteride studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
Claims that go past the evidence
Things said about this substance that sound reasonable, and the exact step that is missing between the evidence and the claim.
✗Goes past the evidence
That preventing biopsy-detected cancer prevents prostate cancer death — REDUCE had no mortality endpoint and reported no survival result
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That inhibiting both 5-alpha-reductase isoenzymes beats inhibiting one — EPICS randomised 1,630 men against finasteride and found no difference
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the 22.8% detection reduction is unaffected by biopsying a gland a quarter smaller than the comparator gland
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the twice-observed cardiac failure imbalance is either a real drug effect or safely dismissible; it is an unadjudicated composite in trials not designed to measure it
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
What is missing or unclear◇Read from sources, not yet reviewed
What nobody knows yet
Open questions, each with why it is open and what would close it.
Missing populations
Which groups were under-represented in the studies has not been recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing long-term data
No completed tested study window is recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
No reviewed conclusion
RNAWiki has not yet published a reviewed conclusion for this use.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing interaction studies
No interaction was found in the registers checked. Not finding one is not the same as showing there is none.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Formulation uncertainty
Several salts, forms or products of Dutasteride are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Every line above can be traced to the study named beside it. Follow the link and read it.
Fewer catheters and fewer operations, in 4,325 randomised men over two years
In plain words
This is the one drug on these pages with a randomised result on something other than a questionnaire. Over two years it cut the risk of being unable to pass urine at all by 57%, and the risk of needing prostate surgery by 48%.
What was measured
Relative risk of acute urinary retention and of BPH-related surgery at 24 months, plus prostate volume and dihydrotestosterone change
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The pooled ARIA3001, ARIA3002 and ARIA3003 trials randomised 4,325 men with moderate-to-severe symptoms to dutasteride 0.5 mg or placebo for 24 months, with 2,951 completing. At 24 months serum dihydrotestosterone fell 90.2% (median -93.7%, p<0.001), total prostate volume fell 25.7% (p<0.001) and transition zone volume 20.4% (p<0.001). Symptom score improved 4.5 points, or 21.4% (p<0.001), and maximum flow rate rose 2.2 mL/sec (p<0.001). Risk of acute urinary retention fell 57% and risk of BPH-related surgical intervention fell 48% against placebo.
Written into the record, not signed off as a reviewed claim
REDUCE hit its endpoint and produced a warning rather than an indication
In plain words
An 8,231-man, four-year trial was built to show this drug prevents prostate cancer. Fewer cancers were found on biopsy, exactly as designed. But the aggressive ones went the wrong way, and the label now carries that finding as a warning instead of a prevention claim.
What was measured
Biopsy-detected prostate cancer over four years, and Gleason 8-10 incidence by treatment arm
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
REDUCE (NCT00056407) randomised men aged 50 to 75 with a PSA of 2.5 to 10.0 ng/mL and one prior negative biopsy to dutasteride 0.5 mg or placebo for four years; 6,729 underwent biopsy or prostate surgery. Cancer was detected in 659 of 3,305 on dutasteride against 858 of 3,424 on placebo, a relative risk reduction of 22.8% (95% CI 15.2 to 29.8, p<0.001). Gleason 7-10 tumours were 220 against 233 (p=0.81). In years three and four, Gleason 8-10 tumours numbered 12 on dutasteride against 1 on placebo (p=0.003). The current US label states the incidence of Gleason 8-10 prostate cancer as 1.0% on dutasteride against 0.5% on placebo, and notes the same pattern for finasteride in a seven-year trial, 1.8% against 1.1%. There is no prostate-cancer-prevention indication for either drug.
Written into the record, not signed off as a reviewed claim
The endpoint was cancer found on a biopsy, not cancer that harms anyone
In plain words
The prevention trial counted tumours found by scheduled biopsies. It did not count deaths, and it did not follow men long enough to know whether the cancers it prevented were ones that would ever have caused trouble.
What was measured
That preventing a biopsy-detectable cancer is the same as preventing a harmful one, in a trial with no mortality endpoint and a systematic difference in the size of the organ being sampled
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The registered primary outcome of NCT00056407 is the incidence of biopsy-detectable prostate cancer at years two and four, reported three ways as crude rate, modified crude rate and restricted crude rate. Prostate-cancer mortality is not among the primary outcomes and the four-year report carries no survival result. A large fraction of biopsy-detected, low-Gleason prostate cancer is never destined to become clinically significant, which is why the field moved towards active surveillance over the same decade. So the 22.8% figure describes how many cancers a scheduled biopsy programme found, in a drug arm where the gland being biopsied was roughly a quarter smaller.
Written into the record, not signed off as a reviewed claim
A cardiac failure imbalance appeared in both large trials and was never explained
In plain words
Two separate multi-thousand-man trials of this drug reported more heart failure in the treated arms than expected. Neither trial was designed to test that, and no mechanism has been established.
What was measured
Incidence of the composite adverse-event term cardiac failure, by arm
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
In REDUCE, the composite term of cardiac failure occurred in 0.7% on dutasteride against 0.4% on placebo (p=0.03) across 8,231 randomised men. The four-year CombAT report separately notes an imbalance in the composite term of cardiac failure across its three arms, in a further 4,844 men. Neither trial had cardiac failure as an endpoint, neither adjudicated it, and the term is a composite rather than a single diagnosis. That combination — an unplanned finding, unadjudicated, in a composite, appearing twice — is exactly the shape of finding that is neither dismissible nor conclusive.
Written into the record, not signed off as a reviewed claim
Dual isoenzyme inhibition was the reason for the drug and did not beat finasteride
In plain words
Dutasteride blocks both versions of the enzyme where finasteride mainly blocks one. The trial run to show that this matters clinically found no difference.
What was measured
That inhibiting both 5-alpha-reductase isoenzymes rather than one produces a better clinical result — a mechanistic argument the head-to-head trial did not confirm
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
EPICS randomised 1,630 men aged 50 and over with symptomatic BPH — 813 to dutasteride and 817 to finasteride — for a 48-week blinded phase with an optional 24-month open-label extension. Both drugs reduced prostate volume with no significant difference between them, and improvements in the AUA Symptom Index and maximum urinary flow rate were similar. A similar percentage of adverse events occurred in both groups. The greater biochemical suppression of dihydrotestosterone that dual inhibition produces is real and measurable; the clinical superiority that was inferred from it was not found.
Written into the record, not signed off as a reviewed claim
It halves PSA, which is the test used to look for the cancer it warns about
In plain words
This drug cuts the PSA blood test result roughly in half. That is the same test used to decide whether a man needs investigating for prostate cancer, and the drug carries a high-grade cancer warning.
What was measured
Percentage reduction in serum prostate-specific antigen on treatment
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The US label states that dutasteride reduces serum PSA concentration by approximately 50%, and that any confirmed increase from the nadir while on treatment may signal prostate cancer and should be evaluated even if PSA values are still within the normal range for men not taking a 5-alpha-reductase inhibitor. The interaction is not subtle: the drug suppresses the marker by a factor of two and simultaneously carries a Warnings and Precautions entry for increased Gleason 8-10 incidence. Both facts are on the same label, several pages apart.
Source
US prescribing information for dutasteride, Warnings and Precautions and Clinical Pharmacology sections (openFDA drug label endpoint)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Stopping the drug does not stop the exposure for four to six months
In plain words
The terminal half-life is about five weeks, so the drug is still measurable in blood four to six months after the last capsule. Blood donation is deferred for six months for that reason.
What was measured
Terminal elimination half-life and duration of detectable serum concentration after discontinuation
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The label gives a terminal elimination half-life of approximately five weeks at steady state, with serum concentrations remaining detectable above 0.1 ng/mL for four to six months after discontinuation. Men treated with dutasteride are instructed not to donate blood until at least six months after the last dose, so that a pregnant transfusion recipient is not exposed; 5-alpha-reductase inhibitors can interfere with development of the external genitalia of a male fetus. This pharmacokinetic tail also means that adverse effects attributed to the drug cannot be resolved by a short washout, and that any trial of discontinuation has to allow months rather than weeks.
Source
US prescribing information for dutasteride, Clinical Pharmacology and Warnings and Precautions sections (openFDA drug label endpoint)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
How many documents were read
20 documents were read for this substance.
RNAWiki source record
20 of them state the same halfLife, and they agree.
RNAWiki source record
20 of them state the same bioavailability, and they agree.
RNAWiki source record
20 of them state the same tMax, and they agree.
RNAWiki source record
20 of them state the same volumeOfDistribution, and they agree.
RNAWiki source record
Where else this substance is registered
FDA substance identifier (UNII)
O0J6XJN02I
RxNorm concept
351172
Checks this page had to pass
✓ Passed
Identity resolved
no open identity hold
✓ Passed
No unresolved merge across substance families
no quarantine open
✓ Passed
Every public sentence names a source
The opening statement carries the origin: Written into the record, not signed off.
✗ Not passed
Trial roles classified for highlighted evidence
No registered study is classified as testing this substance.
✓ Passed
No internal keys in reader text
enforced by the copy-contract test over the rendered page
✓ Passed
Safety mode resolved
Suppression classes recorded: S3.
✓ Passed
Canonical metadata present
slug and display name present
What is missing or unclear◇Read from sources, not yet reviewed
How this medicine reached us
Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.
What the approval register records
25 approved applications cover products containing this substance. The earliest was NDA021319, approved 20011120 to WAYLIS THERAP.
This order is fixed in code and does not count clicks or time on the page.
What is not here
3 questions this page could not answer
These sections were prepared and left out because there was nothing to put in them. They are listed rather than hidden, so the gaps in this record are visible.
What it may clash with — found nothing in the sources checked.
Other ways to the same goal — found nothing in the sources checked.
What changed on this page — found nothing in the sources checked.
The record as stored
The full record, for auditing
Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.
The older medicine-wide conclusion held in this record
Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.
A dual 5-alpha-reductase inhibitor that cuts circulating dihydrotestosterone by about 90% and shrank the prostate 25.7% over two years in 4,325 men, cutting acute urinary retention by 57% and BPH surgery by 48% — and the same androgen suppression, tested for four years in 8,231 men to prevent prostate cancer, produced twelve Gleason 8-10 tumours against one on placebo in years three and four, which is why the label carries a warning where an indication was expected.
Recorded evidence blocks (13)
Q2
What did Dutasteride's largest trial (54459 people) and its longest (16 years) measure?
54459 people in Dutasteride's largest registered study, 16 years in its longest registered window, measuring Growth Hormone concentration after injections. ClinicalTrials.gov · 2026-09-01
26 phase2, 20 phase3, 15 phase1, 15 phase4, 11 na, 10 na or unstated, 1 early phase1; NCT01653925; 2026-12. Last human test completed 2024, NCT04098302.
Interpretation These counts include studies where Dutasteride was a comparison treatment, a background treatment or an exposure in an observational study, and the longest window may be a planned end date. Trial roles have not yet been classified for this record.
Show the evidence
phase2
26
phase3
20
phase1
15
phase4
15
na
11
na or unstated
10
2 more recorded rows
early phase1
1
Last recorded human testNCT04098302
2024-06-28
recorded 2026-09-01 · last checked 2026-09-04
Q3
Dutasteride was tested only in human — what did it show?
Dutasteride's half-life is 170 hours — which schedules were studied?
170 hours, the half-life Dutasteride's label states. openfda-label · 170f01fe-5048-413c-b4cd-8311e1a2728a · 2026-08-30
bioavailability 60% %.
Show the evidence
half life
170 hours hours; In this single-dose trial, dutasteride half-life increased with age (approximately 170 hours in men aged 20 to 49 years, approximately 260 hours in men aged 50 to 69 years, and approximately 300 hours in men older than 70 years).
tmax
12.3 Pharmacokinetics Absorption Following administration of a single 0.5-mg dose of a capsule, time to peak serum concentrations (T max ) of dutasteride occurs within 2 to 3 hours.
bioavailability
60% %; Absolute bioavailability in 5 healthy subjects is approximately 60% (range: 40% to 94%).
metabolism
Metabolism and Elimination Dutasteride is extensively metabolized in humans.
recorded 2026-08-30 · last checked 2026-09-04
Q7
Which of an adverse event, androgen receptor related mutations and area under curve of tadalafil did Dutasteride's trials measure?
an adverse event, androgen receptor related mutations and area under curve of tadalafil lead 40 outcome terms across Dutasteride's trials. ClinicalTrials.gov · 2026-09-01
Interpretation lipid profile, elevations in serum testosterone, growth hormone concentration after injections, time to disease progression, toxicity and prostate specific antigen follow.
Show the evidence
biopsy detectable prostate cancer at years 2 and 4
1
bone metabolism
1
insulin resistance
1
lipid profile
1
elevations in serum testosterone
1
growth hormone concentration after injections
1
14 more recorded rows
time to disease progression
1
toxicity
1
prostate specific antigen
1
testosterone concentration
1
dihydrotestosterone concentration
1
fat free mass measured by dexa scanning
1
total prostate volume
1
lapatinib maximum tolerated dose
1
lapatinib dose limiting toxicity
1
plasma lapatinib levels
1
insulin sensitivity
1
intratesticular testosterone level
1
intratesticular dihydrotestosterone level
1
intratesticular androstenedione level
1
recorded 2026-09-01 · last checked 2026-09-04
Q8
Which of Dutasteride's 9 ongoing trials reports first?
Quality of Life Was Measured by the Expanded Prostate Cancer Index Composite (EPIC) Hormonal Health-related Quality of Life Questionnaire; Effects of the Interventions on Lipid Metabolism From Blood and Prostatic Microenvironment; latest 2032-04-02
Show the evidence
Trial
NCT01342367
"Feasibility of Hormones and Radiation for Intermediate or High Risk Prostate Cancer"; n 74; "Quality of Life Was Measured by the Expanded Prostate Cancer Index Composite (EPIC) Hormonal Health-related Quality of Life Questionnaire"; 2026-02
NCT01653925
"Molecular Mechanisms of Dutasteride and Dietary Interventions to Prevent Prostate Cancer and Reduce Its Progression"; n 120; "Effects of the Interventions on Lipid Metabolism From Blood and Prostatic Microenvironment"; 2026-12
NCT05513365
"Phase II Dutasteride in Combination With CAB vs CAB in SDC"; n 26; "Overall Response Rate (ORR)"; 2027-09
NCT06001619
"Prostate Medication, Metabolism and Gut Microbiota"; n 100; "Gut microbiota signature before 5-ARI therapy"; 2026-12-31
NCT06916793
"A Phase 3 Study to Evaluate the Safety and Efficacy of CKD-843 in Male Patients With Androgenetic Alopecia"; n 288; "Total number of hair Changes"; 2027-09-17
NCT07065682
"Effetivity of Dutasteride and Aloe Vera Extract Combination on Angiogenesis and Obstruction on Benign Prostatic Hyperplasia"; n 84; "Uroflowmetry result"; 2027-12-01
3 further recorded trials
NCT07417449
"Impact of Long-term Dutasteride Use on Perioperative Outcomes of HoLEP"; n 1000; "Change in Hemoglobin Levels (Hemoglobin Drop)"; 2027-04-01
NCT07420517
"Dutasteride in Patients With Low Grade Non-muscle Invasive Bladder Cancer"; n 95; "Incidence of NMIBC recurrences in patients treated with dutasteride"; 2032-04-02
NCT07421804
"Evaluation of Topical Dutasteride as a Potential New Therapy for Facial Acne Vulgaris Versus the Triple Combination Therapy (Clindamycin Phosphate 1.2%, Benzoyl Peroxide 3.1%, and Adapalene 0.15% Gel)"; n 50; "Evaluate and compare the therapeutic efficacy (clinical, microbiological & psychological) of topical Dutasteride 0.05% versus topical fixed-dose Clindamycin Phosphate 1.2%, Benzoyl Peroxide 3.1%, and Adapalene 0.15% gel in patients with…"; 2028-04
recorded 2026-09-01 · last checked 2026-09-04
Q9
Which 42 trials of Dutasteride posted no result?
Posted no result
42 of 42 completed trials
Registrations
NCT00062790, NCT00161421, NCT00802321, NCT00399165, NCT00375765 and NCT00146146, and 36 more
Completion dates
oldest 2005-07; newest 2023-08-11
Show the evidence
Trial
NCT00062790
2005-07
NCT00161421
2006-07
NCT00802321
2006-11
NCT00399165
2007-05
NCT00375765
2007-07
NCT00146146
2008-01
14 further recorded trials
NCT00680680
2008-02
NCT00309855
2008-08
NCT00827814
2009-04
NCT00880672
2009-04
NCT00382356
2009-07
NCT00493987
2010-03
NCT01337258
2010-07
NCT01381510
2010-08
NCT01525914
2010-08
NCT00780754
2010-12
NCT01376258
2010-12
NCT00883909
2010-12-29
NCT01577693
2011-08-31
NCT01471678
2011-09-07
Q10
At the median, Dutasteride's trials enrolled 55.5 people — anything larger?
Median enrolment
55.5
Largest enrolment
54459
Registered trials counted
90
Q11
What do 433 spontaneous reports say about Dutasteride — and not say?
These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.
Dutasteride appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 433 reaction mentions were counted: prostate cancer 72; urinary retention 64; gynaecomastia 58; orthostatic hypotension 48. open-targets-adr · CHEMBL1200969 · 2026-06-24
Show the evidence
prostate cancer
72
urinary retention
64
gynaecomastia
58
orthostatic hypotension
48
erectile dysfunction
44
cardiac failure
35
4 more recorded rows
hepatic function abnormal
32
gamma-glutamyltransferase increased
29
breast cancer
26
breast pain
25
recorded 2026-06-24 · last checked 2026-09-04
Q12
Dutasteride and CYP3A4, CYP1A2 and CYP2C19: shared by which compounds?
CYP3A4, CYP1A2 and CYP2C19 appear in Dutasteride's recorded interaction sentences, 19 in all. openfda-label+europepmc · 2026-08-30
Interpretation pharmacokinetics
Show the evidence
CYP1A2
pharmacokinetics
Dutasteride is not metabolized in vitro by human cytochrome P450 isoenzymes CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1.
pharmacokinetics
Dutasteride does not inhibit the in vitro metabolism of model substrates for the major human cytochrome P450 isoenzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) at a concentration of 1,000 ng/mL, 25 times greater than steady-state serum concentrations in humans.
CYP2A6pharmacokinetics
Dutasteride is not metabolized in vitro by human cytochrome P450 isoenzymes CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1.
CYP2B6pharmacokinetics
Dutasteride is not metabolized in vitro by human cytochrome P450 isoenzymes CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1.
CYP2C19
pharmacokinetics
Dutasteride is not metabolized in vitro by human cytochrome P450 isoenzymes CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1.
pharmacokinetics
Dutasteride does not inhibit the in vitro metabolism of model substrates for the major human cytochrome P450 isoenzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) at a concentration of 1,000 ng/mL, 25 times greater than steady-state serum concentrations in humans.
CYP2C8pharmacokinetics
Dutasteride is not metabolized in vitro by human cytochrome P450 isoenzymes CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1.
CYP2C9
pharmacokinetics
Dutasteride is not metabolized in vitro by human cytochrome P450 isoenzymes CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1.
pharmacokinetics
Dutasteride does not inhibit the in vitro metabolism of model substrates for the major human cytochrome P450 isoenzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) at a concentration of 1,000 ng/mL, 25 times greater than steady-state serum concentrations in humans.
CYP2D6
pharmacokinetics
Dutasteride is not metabolized in vitro by human cytochrome P450 isoenzymes CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1.
pharmacokinetics
Dutasteride does not inhibit the in vitro metabolism of model substrates for the major human cytochrome P450 isoenzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) at a concentration of 1,000 ng/mL, 25 times greater than steady-state serum concentrations in humans.
CYP2E1pharmacokinetics
Dutasteride is not metabolized in vitro by human cytochrome P450 isoenzymes CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1.
CYP3A4
pharmacokinetics
In vitro studies showed that dutasteride is metabolized by the CYP3A4 and CYP3A5 isoenzymes.
pharmacokinetics
In addition, the 15-hydroxydutasteride metabolite was formed by CYP3A4.
pharmacokinetics
Dutasteride does not inhibit the in vitro metabolism of model substrates for the major human cytochrome P450 isoenzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) at a concentration of 1,000 ng/mL, 25 times greater than steady-state serum concentrations in humans.
pharmacokinetics
However, based on in vitro data, blood concentrations of dutasteride may increase in the presence of inhibitors of CYP3A4/5 such as ritonavir, ketoconazole, verapamil, diltiazem, cimetidine, troleandomycin, and ciprofloxacin.
pharmacokinetics
Calcium Channel Antagonists: In a population pharmacokinetics analysis, a decrease in clearance of dutasteride was noted when coadministered with the CYP3A4 inhibitors verapamil (-37%, n = 6) and diltiazem (-44%, n = 5).
pharmacokinetics
In contrast, no decrease in clearance was seen when amlodipine, another calcium channel antagonist that is not a CYP3A4 inhibitor, was coadministered with dutasteride (+7%, n = 4).
CYP3A5pharmacokinetics
In vitro studies showed that dutasteride is metabolized by the CYP3A4 and CYP3A5 isoenzymes.
recorded 2026-08-30 · last checked 2026-09-04
Q13
Was Dutasteride studied with fasting?
fasting is named in Dutasteride's label sentences: "We calculated HOMA-IR from baseline fasting glucose and insulin, then stratified patients into quartiles within each arm (placebo vs. dutasteride)." openfda-label+europepmc · 2026-08-30
1 recorded statement; fasting
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fasting
We calculated HOMA-IR from baseline fasting glucose and insulin, then stratified patients into quartiles within each arm (placebo vs. dutasteride).
recorded 2026-08-30 · last checked 2026-09-04
Q14
What is recorded about Dutasteride and autophagy?
"Meanwhile, the autophagy inhibitor (3-methyladenine) and SRD5A1 inhibitor (Dutasteride) were utilized to evaluate their anti-myeloma effect." — where Dutasteride and autophagy appear together. Europe PMC · pathway abstract search · 2021-02-24
autophagy; PMID 33627630, 18465891
Show the evidence
autophagy
PMID 33627630
"Meanwhile, the autophagy inhibitor (3-methyladenine) and SRD5A1 inhibitor (Dutasteride) were utilized to evaluate their anti-myeloma effect."
PMID 18465891
"Dutasteride inhibits the mitochondrial transition pore and induces an increase of autophagosomal structures in human cell lines."
recorded 2021-02-24 · last checked 2026-09-04
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