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Estrogens, Conjugated

  • Hormone
  • Prescription only
  • Identity checked
  • Sources last checked 2026-09-04

This page shows what was measured, who it was measured in, and what that does not settle.

What Estrogens, Conjugated does in the body

Treatment of Moderate to Severe Vasomotor Symptoms due to Menopause ( 1.1 )

Endogenous estrogens are largely responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Although circulating estrogens exist in a dynamic equilibrium of metabolic interconversions, estradiol is the principal intracellular human estrogen and is substantially more potent than its metabolites, estrone and estriol, at the receptor level. The primary source of estrogen in normally cycling adult women is the ovarian follicle, which secretes 70 to 500 mcg of estradiol daily, depending on the phase of the menstrual cycle. After menopause, most endogenous estrogen is produced by conversion of androstenedione, secreted by the adrenal cortex, to estrone in the peripheral tissues.

Why people take it. Treatment of Moderate to Severe Vasomotor Symptoms due to Menopause ( 1.1 )

What happened in people

RNAWiki has not yet published a reviewed conclusion for this use.

A fixed RNAWiki sentence

Where this came from

Wording RNAWiki always uses, not a finding about this substance.

No reviewed claim names a result for any goal on this record.

No source is stored against this line.

The limit that matters most

Not recorded.

Where it acts
Not recorded.
Kind of result
No result is published, so no kind of result applies yet
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 mixture.

    FDA substance registry · IU5QR144QX · read 2026-08-29

Where each sentence above came from

The use the label states, quoted from it. No plain-language version of this sentence has been written.

The use the label states, quoted from it. It is written for a clinician, not for a reader without medical training.

No statement of the main limit is recorded.

The four opening statements run to 140 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.

Enzyme

An enzyme is a protein that speeds up one chemical change.

A picture of it, and where the picture fails

An enzyme is like a machine on a production line doing one cut.

Where that stops being true. A machine is switched on and off by a person. Enzymes are controlled by the cell.

What people get wrong. Enzymes are thought to be used up. They are not; they work again and again.

A catalytic protein that lowers the activation energy of a specific reaction.

Receptor

A receptor is a part of a cell that a signal fits into.

A picture of it, and where the picture fails

A receptor is like a lock waiting for one key.

Where that stops being true. A lock either opens or does not. A receptor can be half-triggered, or worn out.

What people get wrong. Fitting a receptor is read as causing a benefit. It causes a step, and nothing more.

A protein that binds a specific ligand and converts that binding into a cellular response.

Pathway

A pathway is a chain of steps inside a cell, each one setting off the next.

A picture of it, and where the picture fails

A pathway is like a row of dominoes.

Where that stops being true. Dominoes fall one way. Pathways loop back and can switch themselves off.

What people get wrong. Changing one step is read as changing the outcome. Other steps often absorb it.

An ordered series of molecular interactions producing a defined cellular change.

What happened in peopleRead 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 26 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.
GoalLife outcomeWhat a body can doHow a person feelsA test resultA step in the bodyHarmsHow longWho was studied
CholesterolNothing 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 moved1 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.
Body weightNothing 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 moved1 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.
Fertility and sexual healthNothing 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.
PainNothing 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.Waiting for a reviewer1 registered symptom measure.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
Cholesterol
hdl subpopulation distribution and composition
Body weight
total body fat mass
Fertility and sexual health
female sexual function index
Pain
pain sex

Sorted by fixed word lists, version v1. A name the rules do not recognise stays unsorted rather than moving to the nearest column.

What each mark on this table means
Nothing in the sources checked
No registered study lists a life outcome for this goal.
Only a number moved
1 registered test measure.
Not recorded
Harms were not a registered measure for this goal.
Waiting for a reviewer
Who was studied is listed further down the page.

What happened in peopleRead from sources, not yet reviewed

What happened in people

Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.

To evaluate the effects of Bazedoxifene/Conjugate Estrogens (CE) combinations on the incidence of endometrial hyperplasia in postmenopausal women.

The study did not show it

Who was studied
NCT00675688
How many people
3544
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
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. 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.

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot
  • Europe PMC · a recorded source, not a stored snapshot

Myocardial Infarction

The study did not show it

Who was studied
NCT00319566
How many people
2430
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
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. 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.

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot
  • Europe PMC · a recorded source, not a stored snapshot

Recurrence-free survival (RFS)

The study did not show it

Who was studied
NCT04266249
How many people
2175
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
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. 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.

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot
  • Europe PMC · a recorded source, not a stored snapshot

Estrogen Replacement Therapy in Treating Women With Early-Stage Endometrial Cancer

The study did not show it

Who was studied
NCT00002976
How many people
2108
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
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. 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.

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot
  • Europe PMC · a recorded source, not a stored snapshot

Percentage of Participants With Endometrial Hyperplasia at Month 12: Main Study

The study did not show it

Who was studied
NCT00808132
How many people
1886
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
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. 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.

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot
  • Europe PMC · a recorded source, not a stored snapshot

Percentage of Participants With Hyperplasia at Screening

The study did not show it

Who was studied
NCT00242710
How many people
1083
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
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. 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.

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot
  • Europe PMC · a recorded source, not a stored snapshot
What we know
RNAWiki holds 6 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 peopleRead 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.

  1. Living longer, or avoiding a major event No evidence recorded. Death, a heart attack, a stroke, a hospital stay.0 registered measures of this kind. 1 written-up study measured this and did not show a benefit.
  2. What a body can do day to day No evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
  3. Measured performance No evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
  4. Symptoms and quality of life Evidence recorded. Pain, tiredness, mood, sleep, as the person rated it.2 registered measures of this kind.
  5. A number that stands in for health Evidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.5 registered measures of this kind.
  6. A step measured inside a person Evidence recorded. Something measured in human tissue or human cells.1 registered measure inside human tissue.
  7. Animals Evidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in Mouse. A result in animals says what to test next. It does not say what happens in people.
  8. Cells in a dish Evidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
  9. A guess from software No 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 would be like to takeRead 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.

  • global impression of improvement
  • pain sex

Measured

Things only a test, a scale or a device shows.

  • hdl subpopulation distribution and composition
  • total body fat mass
  • bone mineral density
  • endometrial biopsy and histological examination
  • flow mediated dilation of the brachial artery
  • prevalence of urinary tract infections

Meaningful

Things that change how a life goes, not only a number.

No registered study measured anything of this kind.

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 (18)
  • total abdominal fat area
  • visceral abdominal fat area
  • areal bone density by dxa
  • pharmacokinetic parameters
  • estradiol
  • moderate to severe hot flushes week 4 itt population
  • moderate to severe hot flushes week 12 itt population
  • vaginal wall composition epithelium
  • vaginal wall composition muscularis
  • vaginal wall composition lamina propria
  • vaginal dryness
  • relative abundance of lactobacillus
  • female sexual function index
  • vaginal itching
  • vaginal irritation
  • visual analog scale
  • glomerular filtration rate
  • vaginal ph as measured by ph strips

These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.

What is missing or unclearRead 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

No description of who was studied is recorded.

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: “Estrogen therapy has been used for the induction of puberty in adolescents with some forms of pubertal delay.”

    US prescribing information · ce793f9e-0c20-43e6-9dc0-064e5c82e243 · read 2026-08-30

  • On older people, the label states: “There have not been sufficient numbers of geriatric patients involved in studies utilizing Conjugated Estrogens Tablets to determine whether those over 65 years of age differ from younger subjects in their response to Conjugated Estrogens Tablets.”

    US prescribing information · ce793f9e-0c20-43e6-9dc0-064e5c82e243 · read 2026-08-30

  • On people who are pregnant, the label states: “Risk Summary Conjugated Estrogens Tablets are not indicated for use during pregnancy.”

    US prescribing information · ce793f9e-0c20-43e6-9dc0-064e5c82e243 · read 2026-08-30

  • On people who are breastfeeding, the label states: “Risk Summary Estrogens and progestins and metabolites are present in human milk.”

    US prescribing information · ce793f9e-0c20-43e6-9dc0-064e5c82e243 · read 2026-08-30

  • On people with reduced liver function, the label states: “The effect of hepatic impairment on the pharmacokinetics of Conjugated Estrogens Tablets has not been studied.”

    US prescribing information · ce793f9e-0c20-43e6-9dc0-064e5c82e243 · read 2026-08-30

  • On people with reduced kidney function, the label states: “The effect of renal impairment on the pharmacokinetics of Conjugated Estrogens Tablets has not been studied.”

    US prescribing information · ce793f9e-0c20-43e6-9dc0-064e5c82e243 · read 2026-08-30

Where the result stopped carrying

  • 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 takeRead 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 takeRead 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

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

No form or route is recorded.

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: S6.

No source is stored against this line.

What is in the pack

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

Nothing is recorded about product quality.

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 takeNothing found in the sources checked

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.

Nothing found in the sources checked

No harm is recorded against this substance in the sources RNAWiki checked. Finding nothing is not the same as showing there is nothing.

The sources listed were searched and held nothing. That is not the same as nothing existing.

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.

Estrogens, Conjugated appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 1292 reaction mentions were counted. One report can name several reactions.

The recorded terms (10)
  • breast cancer — 223 reaction mentions
  • drug hypersensitivity — 210 reaction mentions
  • hot flush — 190 reaction mentions
  • feeling abnormal — 115 reaction mentions
  • depression — 111 reaction mentions
  • insomnia — 111 reaction mentions
  • vaginal haemorrhage — 92 reaction mentions
  • vulvovaginal burning sensation — 92 reaction mentions
  • alopecia — 83 reaction mentions
  • burning sensation — 65 reaction mentions
  • 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 unclearRead 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

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

The exact form studied is not recorded.

No source is stored against this line.

What is sold

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

Nothing further is recorded about which forms are sold.

No source is stored against this line.

What is recorded as being sold

  • 45 products list this as an active ingredient in the United States drug directory. 32 of them contain it and nothing else.

    FDA National Drug Code directory · 42816-1102 · read 2026-08-29

  • They are sold as cream, injection, powder, lyophilized, for solution, liquid, powder, tablet, film coated and tablet, sugar coated, taken intramuscular, intravenous, oral and vaginal.

    FDA National Drug Code directory · 42816-1102 · read 2026-08-29

  • The regulator's established pharmacologic class for it is conjugated (usp) [cs], estrogen receptor agonists [moa] and estrogen [epc].

    FDA National Drug Code directory · 42816-1102 · read 2026-08-29

  • 15 published labels name it as an active ingredient. 9 of them describe this substance alone, which is where its own label text on this page comes from.

    US prescribing information · 87e2da8d-432c-4ed5-67a1-dc26294b2295 · read 2026-08-29

  • Those labels are classed as human otc drug and human prescription drug.

    US prescribing information · 87e2da8d-432c-4ed5-67a1-dc26294b2295 · read 2026-08-29

  • 506 marketed supplement labels list this ingredient, classed as fat/fatty acid.

    NIH Dietary Supplement Label Database · 242725 · read 2026-08-29

  • Those labels carry all other, nutrient and structure/function claims. A claim of that kind is written by the manufacturer and is not assessed by any regulator, so its presence says nothing about whether it is true.

    NIH Dietary Supplement Label Database · 242725 · read 2026-08-29

  • Conjugated Estrogens is oral at 3 DOSAGE FORMS AND STRENGTHS Conjugated Estrogens Tablets, USP Tablet Strength Tablet Shape/Color Imprint 0.3 mg oval/green PREMARIN 0.3 0.45 mg oval/blue PREMARIN 0.45 0.625 mg oval/maroon PREMARIN 0.625 0.9 mg oval/wh…, recorded as fda label in effect 2026-02-27 in the United States.

    US prescribing information · ce793f9e-0c20-43e6-9dc0-064e5c82e243 · read 2026-08-30

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 takeRead 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 Estrogens, Conjugated 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 unclearRead from sources, not yet reviewed

What nobody knows yet

Open questions, each with why it is open and what would close it.

How much did people take in the studies?

The sources RNAWiki checked hold nothing for this field.

Why it matters. A result belongs to an amount. Without the amount the result floats free.

What would answer it

A stored source that records 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.

How fast does the body clear it?

The sources RNAWiki checked hold nothing for this field.

Why it matters. Without this, nothing on this page can say how long anything lasts.

What would answer it

A stored source that records 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 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

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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 Estrogens, Conjugated 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 peopleRead 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.

Where else this substance is registered

FDA substance identifier (UNII)
IU5QR144QX
RxNorm concept
197660

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What is missing or unclearRead 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

  • 11 approved applications cover products containing this substance. The earliest was NDA004782, approved 19420508 to WYETH PHARMS.

    Drugs@FDA application register · NDA004782 · read 2026-08-29

  • Marketing status on the register: discontinued and prescription.

    Drugs@FDA application register · NDA004782 · read 2026-08-29

  • The earliest marketing start date recorded for a listed product is 19561201.

    FDA National Drug Code directory · 42816-1102 · read 2026-08-29

What is missing or unclearRead from sources, not yet reviewed

What to learn next

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What is not here

6 questions this page could not answer

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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.

Recorded evidence blocks (10)

What did Estrogens, Conjugated's largest trial (7525 people) and its longest (13 years) measure?


7525 people in Estrogens, Conjugated's largest registered study, 13 years in its longest registered window, measuring HDL subpopulation distribution and composition. ClinicalTrials.gov · 2026-09-01

12 phase4, 10 na, 10 phase3, 9 phase2, 5 phase1, 3 na or unstated; NCT00000466; 2000-10; no ageing endpoint recorded. Last human test completed 2023, NCT02431897.

Interpretation These counts include studies where Estrogens, Conjugated 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
  • phase4
    12
  • na
    10
  • phase3
    10
  • phase2
    9
  • phase1
    5
  • na or unstated
    3
1 more recorded row
  • Last recorded human test NCT02431897
    2023-05-17

recorded 2026-09-01 · last checked 2026-09-04

From mouse to human: where has Estrogens, Conjugated shown mechanism-only?


mouse: mechanism-only and human: mechanism-only (46): the rungs where Estrogens, Conjugated has a recorded finding. Europe PMC and ClinicalTrials.gov · organism ladder · 2026-09-01

Interpretation HDL subpopulation distribution and composition — the recorded outcome words.

Yeast C. elegans Drosophila Mouse mechanism-onlyRat Dog Non-human primate Human mechanism-only
Show the evidence
  • mouse
    mechanism-only
  • human NCT00083824
    mechanism-only; HDL subpopulation distribution and composition; 46

recorded 2026-09-01 · last checked 2026-09-04

5 of Estrogens, Conjugated's trials stopped: accrual/recruitment, other?


accrual/recruitment (4) and other (1): Estrogens, Conjugated's stop wording, clustered. ClinicalTrials.gov · 2026-09-01

"Unable to complete accrual; elected to close the study in April 2008."; 5 of 46 registered studies

Show the evidence

Trial

  • NCT00249847
    terminated; "Unable to complete accrual; elected to close the study in April 2008."
  • NCT01648751
    terminated; "Insufficient recruitment"
  • NCT02860897
    withdrawn; "Unable to provide study medications due to cost."
  • NCT03018106
    terminated; "Obstacles with recruitment"
  • NCT03943823
    terminated; "Difficulties in recruiting and retaining patients due to the COVID pandemic; lack of availability of study drug trimosan; lack of study personnel"

recorded 2026-09-01 · last checked 2026-09-04

Which of areal bone density by dxa, bone mineral density and endometrial biopsy and histological examination did Estrogens, Conjugated's trials measure?


areal bone density by dxa, bone mineral density and endometrial biopsy and histological examination lead 26 outcome terms across Estrogens, Conjugated's trials. ClinicalTrials.gov · 2026-09-01

Interpretation visceral abdominal fat area, areal bone density by dxa, bone mineral density, endometrial biopsy and histological examination, pharmacokinetic parameters and estradiol follow.

Show the evidence
  • hdl subpopulation distribution and composition
    1
  • total body fat mass
    1
  • total abdominal fat area
    1
  • visceral abdominal fat area
    1
  • areal bone density by dxa
    1
  • bone mineral density
    1
14 more recorded rows
  • endometrial biopsy and histological examination
    1
  • pharmacokinetic parameters
    1
  • estradiol
    1
  • moderate to severe hot flushes week 4 itt population
    1
  • moderate to severe hot flushes week 12 itt population
    1
  • flow mediated dilation of the brachial artery
    1
  • global impression of improvement
    1
  • vaginal wall composition epithelium
    1
  • vaginal wall composition muscularis
    1
  • vaginal wall composition lamina propria
    1
  • vaginal dryness
    1
  • relative abundance of lactobacillus
    1
  • female sexual function index
    1
  • pain sex
    1

recorded 2026-09-01 · last checked 2026-09-04

Which of Estrogens, Conjugated's 2 ongoing trials reports first?


2 registered trials of Estrogens, Conjugated are open; earliest completion 2026-12-31. ClinicalTrials.gov · 2026-09-01

Glomerular filtration rate (GFR); Short form of Urinary Distress Inventory (UDI-6); latest 2027-05-01

Show the evidence

Trial

  • NCT03663543
    "Intravenous Estrogen in Kidney Transplant Study"; n 30; "Glomerular filtration rate (GFR)"; 2027-05-01
  • NCT06197295
    "Efficacy of Combined Pharmacotherapy Versus Solifenacin With Vaginal Estrogen Cream for Women With Detrusor Overactivity"; n 200; "Short form of Urinary Distress Inventory (UDI-6)"; 2026-12-31

recorded 2026-09-01 · last checked 2026-09-04

Which 18 trials of Estrogens, Conjugated posted no result?


Posted no result
18 of 18 completed trials
Registrations
NCT00000612, NCT00000466, NCT00000555, NCT00745108, NCT00149604 and NCT00234676, and 12 more
Completion dates
oldest 1998-12; newest 2019-12-31
Show the evidence

Trial

  • NCT00000612
    1998-12
  • NCT00000466
    2000-10
  • NCT00000555
    2003-05
  • NCT00745108
    2005-07-21
  • NCT00149604
    2006-02
  • NCT00234676
    2006-03
12 further recorded trials
  • NCT00083824
    2007-02
  • NCT00318318
    2007-02
  • NCT00026286
    2007-06-15
  • NCT00685009
    2008-03
  • NCT00745173
    2008-10
  • NCT00803335
    2011-05
  • NCT00134654
    2011-06
  • NCT01482416
    2014-08
  • NCT01843166
    2016-12
  • NCT03032848
    2016-12-26
  • NCT03266926
    2018-03-01
  • NCT02869165
    2019-12-31

At the median, Estrogens, Conjugated's trials enrolled 58 people — anything larger?


Median enrolment
58
Largest enrolment
7525
Registered trials counted
41

What do 1292 spontaneous reports say about Estrogens, Conjugated — 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.

Estrogens, Conjugated appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 1292 reaction mentions were counted: breast cancer 223; drug hypersensitivity 210; hot flush 190; feeling abnormal 115. open-targets-adr · CHEMBL1201649 · 2026-06-24

Show the evidence
  • breast cancer
    223
  • drug hypersensitivity
    210
  • hot flush
    190
  • feeling abnormal
    115
  • depression
    111
  • insomnia
    111
4 more recorded rows
  • vaginal haemorrhage
    92
  • vulvovaginal burning sensation
    92
  • alopecia
    83
  • burning sensation
    65

recorded 2026-06-24 · last checked 2026-09-04

Estrogens, Conjugated and CYP3A4: shared by which compounds?


CYP3A4 appear in Estrogens, Conjugated's recorded interaction sentences, 4 in all. openfda-label+europepmc · 2026-08-25

Interpretation drug_interactions

Show the evidence

CYP3A4

  • drug_interactions
    Inducers and/or inhibitors of CYP3A4 may affect estrogen drug metabolism ( 7.1 ) 7.1 Metabolic Interactions In vitro and in vivo studies have shown that estrogens are metabolized partially by cytochrome P450 3A4 (CYP3A4).
  • drug_interactions
    Therefore, inducers or inhibitors of CYP3A4 may affect estrogen drug metabolism.
  • drug_interactions
    Inducers of CYP3A4, such as St. John's Wort ( Hypericum perforatum ) preparations, phenobarbital, carbamazepine, and rifampin, may reduce plasma concentrations of estrogens, possibly resulting in a decrease in therapeutic effects and/or changes in the uterine bleeding profile.
  • drug_interactions
    Inhibitors of CYP3A4, such as erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir and grapefruit juice, may increase plasma concentrations of estrogens and may result in side effects.

recorded 2026-08-25 · last checked 2026-09-04

What is recorded about Estrogens, Conjugated and IGF-1?


"Undoubtedly, oral conjugated estrogens, 0.625 mg/day, through a hepatocellular effect, cause marked modifications in the IGF-1/growth hormone axis, which may have clinical relevance." — where Estrogens, Conjugated and IGF-1 appear together. Europe PMC · pathway abstract search · 1997-10-01

IGF-1; PMID 8147234, 9549049

Show the evidence

IGF-1

  • PMID 8147234
    "Undoubtedly, oral conjugated estrogens, 0.625 mg/day, through a hepatocellular effect, cause marked modifications in the IGF-1/growth hormone axis, which may have clinical relevance."
  • PMID 9549049
    "In the women receiving only conjugated estrogens, increased GH levels and decreased IGF-1 levels were found, which replicated previous research and probably reflected estrogen inhibition of hepatic IGF-1 production with a secondary increase in GH release because of reduced feedback inhibition."

recorded 1997-10-01 · last checked 2026-09-04

Where it is registered
Identifiers, relations and other names

The exact record

ChEMBL id
CHEMBL1201649
CAS number
12126-59-9
RxCUI
4099
Also called
Conjugated estrogens, Estrogen, conjugated (class), Oestrogens conjugated, ce, ce 0.45 mg, conjugated equine estrogen, conjugated equine estrogens, ert, estrogen, CONJUGATED ESTROGENS [MI], CONJUGATED ESTROGENS [USP MONOGRAPH], ESTROGENS, CONJUGATED [EP IMPURITY]
Trade name
Estrogens, conjugated component of duavee, Estrogens, conjugated component of premphase conjugated estrogens, Estrogens, conjugated component of prempro, Estrogens, conjugated component of prempro conjugated estrogens, Premarin, Premarin Vaginal, Estrogen 1517, Premarin / Conjugated Estrogens / Premarin Vaginal / Estrogen 1517
Development code
G03CA57
Salt form
premarin vaginal cream
Sources (8)

Sources

2 more sources
  • openfda-label+europepmc K1:IU5QR144QX ·
  • national registers US, CA ·

ChEMBL ATC CC BY-SA · ClinicalTrials.gov — US Government work · Europe PMC — metadata only, under the recorded legal gate · Open Targets 26.06 — CC0 · derived from this page's own recorded fields; no external licence · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work

How these records are assembled · Which registers were checked

Index-quality checks
  • identity passed: no open identity hold
  • required summary fields resolved: 4 required field(s) not terminal: Best-supported result, Most important common problem, Biggest unanswered question, Human evidence
  • public claims reviewed: 0 reviewed claim(s); drafts are never rendered
  • source coverage passed: 8 source rows
  • no critical contamination: no quarantine open
  • canonical metadata passed: slug and display name present
  • no raw internal fields: enforced by the copy-contract test over the rendered page

This is a record of evidence. It is not medical advice, and it does not say this substance suits you. Nothing here says any substance on RNAWiki is appropriate for a child.