This page shows what was measured, who it was measured in, and what that does not settle.
What Trenbolone does in the body
None in people. It is a cattle growth implant and a controlled substance
Testosterone gets changed by the body into two other things: dihydrotestosterone, which is more potent in the prostate and skin, and oestradiol, which does its own separate job. Trenbolone can be converted into neither. It binds the androgen receptor directly and stays what it is, everywhere. In rats that produces a striking result: at low doses it grows muscle by 35 to 40 percent and protects bone while leaving the prostate and the red blood cell count where they were. At high doses that separation disappears. In the men who use it, it is the compound associated with the highest rates of mood instability, irritability, depressive symptoms and cardiac and liver concerns of any steroid surveyed.
What happened in people
Femoral neck strength increased 28% in skeletally mature orchiectomised rats where testosterone produced no strength gain
✎ 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.
Its recorded molecular formula is C18H22O2, weighing 270.4.
PubChem record · 25015 · 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 147 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.
Biomarker
A biomarker is a number from a test that stands in for something about health.
A picture of it, and where the picture fails
A biomarker is like a fuel gauge.
Where that stops being true. A gauge is wired to the tank. Many biomarkers are only loosely tied to health.
What people get wrong. A better number is read as a better life. Several medicines improved a number and helped nobody.
A measurable indicator used as a substitute for a clinical outcome of interest.
Placebo
A placebo is a dummy treatment given so the real one can be compared with it.
A picture of it, and where the picture fails
A placebo is like a blank control in an experiment.
Where that stops being true. A blank does nothing. People given a placebo often do get better.
What people get wrong. A placebo effect is read as imaginary. The improvement is measured and real.
An inactive intervention matched in appearance to the test intervention, used to control for non-specific effects.
Comparator
A comparator is whatever the treatment was measured against.
A picture of it, and where the picture fails
It is like the other runner in a race.
Where that stops being true. A race has one winner. A study can show both arms improved.
What people get wrong. Results are read without asking what the other group got. Beating nothing is not beating a treatment.
The control condition against which the experimental intervention is assessed.
What happened in people◇Read 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.
No human clinical trial exists. The compound has never been given to a person under an approved protocol
✗ The study did not show it
Who was studied
No human trial of trenbolone has ever been registered for any indication
How many people
0
Study design
None
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Not applicable
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. Oil-based intramuscular injection of the acetate or enanthate ester; lawfully, a subcutaneous ear implant in cattle
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
Prevalence of psychosocial and physical concerns, trenbolone users versus other anabolic steroid users
✓ The study showed what it set out to show
Who was studied
Global Drug Survey 2024 comparative analysis
How many people
1146
Study design
Cross-sectional survey of self-reported harms
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
All between-group differences P < 0.001, phi 0.13 to 0.20 for psychosocial and 0.18 to 0.20 for physical concerns
Repeated elsewhere
Unreplicated
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. Self-report and cross-sectional: establishes association, not causation, and cannot exclude that men who choose trenbolone differ from other steroid users in other ways.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oil-based intramuscular injection of the acetate or enanthate ester; lawfully, a subcutaneous ear implant in cattle
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
RNAWiki holds 3 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 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
Trenbolone
What a person takes: Oil-based intramuscular injection of the acetate or enanthate ester; lawfully, a subcutaneous ear implant in cattle.
The measurement behind this step
In cattle, a compressed pellet implanted subcutaneously behind the ear, usually combined with oestradiol, releasing over the finishing period. In human use, an oil-based intramuscular injection of trenbolone acetate or enanthate prepared outside any pharmaceutical quality system. There is no human dosage form, no pharmacopoeial monograph for a human preparation and no established human dose.
Getting in
Injected as an ester, released slowly
The acetate and enanthate forms are oils injected into muscle. The ester is cleaved off gradually, which is what makes one injection last days to weeks.
╌╌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
Trenbolone acetate and trenbolone enanthate are 17beta esters. Tissue esterases hydrolyse them to free 17beta-hydroxy trenbolone; the longer enanthate chain gives slower release. In cattle the lawful form is a compressed subcutaneous ear implant releasing trenbolone acetate over months.
It is not converted into anything more potent in the prostate or into oestrogen in fat, which is what makes it different from testosterone.
╌╌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
Not a substrate for 5-alpha-reductase and not aromatisable. Testosterone is amplified to dihydrotestosterone in prostate and skin and converted to oestradiol in adipose tissue; trenbolone undergoes neither, so its receptor occupancy is uniform across tissues.
It locks onto the androgen receptor strongly, and also onto the progesterone and stress-hormone receptors, which testosterone barely touches.
╌╌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
High-affinity androgen receptor agonism with appreciable progesterone receptor and glucocorticoid receptor binding. The progestogenic component is the standard explanation for its effect on prolactin and libido, and the glucocorticoid interaction for some of its metabolic and behavioural effects.
Muscle protein synthesis rises; the gonadal axis shuts down
Muscle and bone build. At the same time the brain stops signalling the testes, and with no oestrogen being made from the drug, oestrogen falls too.
╌╌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
Androgen response element transactivation in myonuclei with increased satellite cell number, alongside a rise in mature myostatin protein. Hypothalamic and pituitary androgen receptor agonism suppresses LH and FSH. Because the compound does not aromatise, endogenous oestradiol falls without any drug-derived oestrogen replacing it, a state that has its own consequences for lipid profile, bone and mood.
Large anabolic effect in rats; the worst harm profile in men who use it
In animals, 35 to 40 percent more androgen-sensitive muscle and stronger bone. In the men surveyed, significantly more mood instability, irritability, depression, and heart and liver concerns than other steroid users.
──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
Rodent hypertrophy of 35 to 40% above sham at all doses tested with a 28% gain in femoral neck strength. In 1,146 human steroid users, the 237-man trenbolone subgroup showed significantly higher prevalence of psychosocial and cardiovascular and hepatic concerns, all P < 0.001, with effect sizes phi 0.13 to 0.20.
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 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.
Cattle, lawfully. People, unlawfully — a Global Drug Survey analysis identified 237 men out of 1,146 past-year anabolic steroid users who had injected trenbolone in the preceding twelve months.
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.
Where the result stopped carrying
The 2011 recommendation that trenbolone be studied as an androgen replacement therapy was never taken up; no human trial has been registered in the fifteen years since
Its progesterone and glucocorticoid receptor activity means the "clean androgen" framing is incomplete even in the animal data
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 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 (11)
It was studied for a different goal
The studies measured something else entirely. Nothing in this record points to this reason.
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
Not available
❝ 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
Oil-based intramuscular injection of the acetate or enanthate ester; lawfully, a subcutaneous ear implant in cattle
✎ 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
RNAWiki has not recorded a supervision or regulatory status for this substance.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
No register row and no identity class settled the question.
No source is stored against this line.
What is in the pack
In cattle, a compressed pellet implanted subcutaneously behind the ear, usually combined with oestradiol, releasing over the finishing period. In human use, an oil-based intramuscular injection of trenbolone acetate or enanthate prepared outside any pharmaceutical quality system. There is no human dosage form, no pharmacopoeial monograph for a human preparation and no established human dose.
✎ 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 and what that means for what is in the pack.
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
There is no clinical safety dataset because there has never been a clinical trial. The available human evidence is a cross-sectional comparison within 1,146 steroid users in which the trenbolone subgroup reported significantly more mood instability, irritability, depressive symptoms and cardiovascular and hepatic concerns than users of other steroids, all at P < 0.001. Mechanistically expected effects include complete suppression of endogenous testosterone and gonadotropins, suppression of oestradiol without any aromatised replacement, marked reduction in HDL cholesterol, and progestogenic effects on prolactin. Isolated case reports describe hypercalcaemia. As an oil-based underground injectable, the preparation itself carries sterility and dosing-accuracy risks independent of the drug.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
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.
Trenbolone appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 101 reaction mentions were counted. One report can name several reactions.
The recorded terms (10)
drug abuse — 34 reaction mentions
acute kidney injury — 12 reaction mentions
diabetes mellitus — 9 reaction mentions
secondary hypogonadism — 8 reaction mentions
autoimmune thyroiditis — 7 reaction mentions
ischaemic stroke — 7 reaction mentions
renal infarct — 7 reaction mentions
cardiomyopathy — 6 reaction mentions
polycythaemia — 6 reaction mentions
acne fulminans — 5 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 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
Oil-based intramuscular injection of the acetate or enanthate ester; lawfully, a subcutaneous ear implant in cattle
✎ 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
In human use, an oil-based intramuscular injection of trenbolone acetate or enanthate prepared outside any pharmaceutical quality system. There is no human dosage form, no pharmacopoeial monograph for a human preparation and no established human dose.
✎ 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 which forms are sold and how they compare.
No source is stored against this line.
What is recorded as being sold
6 products list this as an active ingredient in the United States drug directory. 4 of them contain it and nothing else.
FDA National Drug Code directory · 82298-130 · read 2026-08-29
They are sold as implant and powder.
FDA National Drug Code directory · 82298-130 · read 2026-08-29
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.
RNAWiki could not confidently classify this substance, so no self-experiment plan is offered.
Questions worth asking
Which of the trials of Trenbolone 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 trenbolone is prostate-sparing, which held only at the lowest doses in the rat study and reversed at high dose
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 favourable rodent tissue-selectivity profile transfers to human use at multiples of those doses
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 survey association proves causation — it is cross-sectional and self-reported, and this page says so rather than treating it as a trial
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.
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
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 Trenbolone 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.
In rats, 35 to 40 percent muscle gain with prostate and haemoglobin spared at low dose
In plain words
In castrated and intact rats, trenbolone enanthate increased androgen-sensitive muscle mass by 35 to 40 percent and protected bone. At the lowest doses the prostate and the red cell count stayed at normal levels; at high doses the prostate grew by 68 percent.
What was measured
Levator ani/bulbocavernosus mass, bone mineral density, prostate mass and haemoglobin by dose
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Yarrow et al. gave graded doses of trenbolone enanthate, supraphysiological testosterone enanthate or vehicle to intact and orchiectomised 3-month-old male F344 rats for 29 days. All trenbolone doses and supraphysiological testosterone increased levator ani and bulbocavernosus muscle mass by 35 to 40% above shams (P <= 0.001), with dose-dependent partial protection against orchiectomy-induced total and trabecular bone mineral density loss (P < 0.05) and against visceral fat accumulation (P < 0.05). The lowest trenbolone doses maintained prostate mass and haemoglobin at sham levels in both intact and orchiectomised animals, while supraphysiological testosterone and high-dose trenbolone raised prostate mass by 84% and 68% respectively (P < 0.01). The tissue separation is real and it is dose-dependent, which is the part usually left out.
Written into the record, not signed off as a reviewed claim
It preserved bone strength in mature rats where testosterone did not
In plain words
In older castrated rats, trenbolone prevented bone density loss and increased femoral neck strength by 28 percent. Testosterone prevented the density loss but did not improve strength, and nearly doubled the prostate.
What was measured
Distal femoral bone mineral density, femoral neck strength and prostate mass in skeletally mature rats
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
McCoy et al. randomised forty 10-month-old male F344/Brown Norway rats to sham, orchiectomy, orchiectomy plus testosterone enanthate 7.0 mg/week, or orchiectomy plus trenbolone enanthate 1.0 mg/week, treating for five weeks. Orchiectomy reduced total and trabecular bone mineral density at the distal femoral metaphysis; both trenbolone and testosterone completely prevented that. Trenbolone additionally increased femoral neck strength by 28% compared with orchiectomised animals (P < 0.05), which testosterone did not. Testosterone nearly doubled prostate mass compared with shams (P < 0.05), while trenbolone did not. The dose ratio matters: 1.0 mg of trenbolone per week did what 7.0 mg of testosterone per week did, and more.
Written into the record, not signed off as a reviewed claim
In 1,146 steroid-using men, the trenbolone group reported more harm on every domain tested
In plain words
A survey of 1,146 men who had used anabolic steroids in the past year compared the 237 who used trenbolone with the 909 who did not. The trenbolone group reported significantly more mood instability, irritability, depression, and heart and liver concerns.
What was measured
Prevalence of self-reported psychosocial and physical concerns, trenbolone versus non-trenbolone steroid users
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Bonenti et al. analysed male respondents to the Global Drug Survey 2024 reporting past-year anabolic-androgenic steroid use (N = 1,146, mean age 31.46, SD 9.93), split into a trenbolone group (n = 237) and a non-trenbolone group (n = 909) by past-12-month injectable trenbolone use. Psychosocial concerns — mood instability, irritability, depressive symptoms — were significantly more common in the trenbolone group (all P < 0.001, phi 0.13 to 0.20). Physical concerns, particularly cardiovascular and hepatic, were also significantly more prevalent (all P < 0.001, phi 0.18 to 0.20). UpSet plots showed denser clustering of co-occurring harms in the trenbolone group. This is self-reported and cross-sectional, so it establishes association rather than causation, and the men who choose trenbolone may differ in other ways. It is nonetheless the largest human dataset that exists on this compound.
Written into the record, not signed off as a reviewed claim
The rat prostate-sparing result is dose-specific and is quoted as if it were not
In plain words
Trenbolone spared the prostate in rats only at the lowest doses tested. At the high dose the prostate grew by 68 percent, which is close to what testosterone did.
What was measured
That trenbolone is prostate-sparing as a property of the molecule, when the animal data show it is a property of the low-dose range only
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
In Yarrow et al. the prostate-sparing and haemoglobin-sparing findings applied to the lowest trenbolone doses. High-dose trenbolone raised prostate mass by 68%, against 84% for supraphysiological testosterone. The muscle effect was 35 to 40% at all doses. So the therapeutic window in that experiment is a low-dose window, and the doses used outside laboratories are chosen for maximum anabolic effect. Citing "trenbolone does not enlarge the prostate" without the dose qualifier inverts the finding: at the doses people actually use, the animal data predict prostate enlargement of the same order as high-dose testosterone.
Written into the record, not signed off as a reviewed claim
It raises myostatin protein while it grows muscle
In plain words
Trenbolone and testosterone both increased mature myostatin protein in rodent muscle at the same time as they increased muscle size and satellite cell number, which is the opposite of the simple story.
What was measured
Mature myostatin protein, muscle mass and satellite cell number in rodent muscle
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Yarrow and colleagues reported that testosterone enanthate and trenbolone enanthate increase mature myostatin protein expression despite increasing skeletal muscle hypertrophy and satellite cell number in rodent muscle. Myostatin is the negative regulator of muscle mass, so a compound that raises it while producing hypertrophy is doing something more complicated than switching off a brake. This matters for the wider claims made about anabolic compounds and myostatin across this whole group of substances: the relationship between the two is not the linear one those claims assume.
Written into the record, not signed off as a reviewed claim
From a proposed androgen replacement therapy to the highest-harm compound in its class
In plain words
The rat papers argued trenbolone had advantages over testosterone and deserved study as a hormone replacement therapy. The human survey data place it at the severe end of the risk range within steroid use.
What was measured
That a favourable low-dose rodent tissue-selectivity profile predicts the human experience of a compound used at multiples of that dose without supervision
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Yarrow et al. concluded in 2011 that their findings indicated trenbolone has advantages over supraphysiological testosterone and supported preclinical study of it as an option for androgen replacement therapy. No such programme followed and no human trial of trenbolone for any indication has ever been registered. The human evidence that did accumulate came from surveys of people using it without supervision: the Global Drug Survey analysis places the trenbolone subgroup at significantly higher prevalence of psychosocial and physical harms than other steroid users, with denser co-occurrence of those harms. These two bodies of evidence are not contradictory — one is low-dose rats and the other is high-dose men — but the distance between them is the whole story of this compound.
This order is fixed in code and does not count clicks or time on the page.
What is not here
7 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 was measured, goal by goal — found nothing in the sources checked.
How close this is to real life — found nothing in the sources checked.
Felt, measured, or meaningful — found nothing in the sources checked.
How long anything takes — found nothing in the sources checked.
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 cattle growth implant and Schedule III anabolic steroid whose rodent pharmacology is unusually clean — muscle and bone preserved without prostate growth at low dose — and whose human record, drawn from 1,146 steroid users, is the worst psychiatric and cardiovascular harm profile in its class.
Recorded evidence blocks (1)
Q1
What do 101 spontaneous reports say about Trenbolone — 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.
Trenbolone appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 101 reaction mentions were counted: drug abuse 34; acute kidney injury 12; diabetes mellitus 9; secondary hypogonadism 8. open-targets-adr · CHEMBL1698011 · 2026-06-24
Show the evidence
drug abuse
34
acute kidney injury
12
diabetes mellitus
9
secondary hypogonadism
8
autoimmune thyroiditis
7
ischaemic stroke
7
4 more recorded rows
renal infarct
7
cardiomyopathy
6
polycythaemia
6
acne fulminans
5
recorded 2026-06-24 · last checked 2026-09-04
Where it is registeredIdentifiers, relations and other names
✗ required summary fields resolved: 5 required field(s) not terminal: Why people use it, 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: 2 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.