This page shows what was measured, who it was measured in, and what that does not settle.
What Boldenone does in the body
A veterinary horse steroid with no approved human use.
Boldenone binds the androgen receptor, the same switch testosterone uses, and turns on the same muscle and bone gene programmes. Two structural details matter. Its long undecylenate ester means one injection releases drug slowly for weeks, so blood levels are flat rather than spiky. And when the body reduces it the way it reduces testosterone, the product is 1-testosterone, a compound that in a rat assay was as strong an androgen as testosterone itself and, unlike testosterone, increased liver weight. Everything else about boldenone is a testing story: bacteria in the gut of cattle and horses convert plant sterols into boldenone, so the drug shows up in animals that were never given it.
What happened in people
Its breakdown product acted like testosterone in rats and also enlarged the liver.
✓ Reviewed first-read answer
Where this came from
A person wrote this and a reviewer approved it against this exact record. It carries no effect size.
A reviewer approved this against this record. The reviewed-claim record carrying the exact population and effect size does not exist yet.
No source is stored against this line.
The limit that matters most
No published human study has measured its claimed lower conversion to oestrogen.
Where it acts
Androgen receptor in skeletal muscle myonuclei, prostate and liver
Kind of result
The kind of result is not recorded
Supervision
RNAWiki has not recorded a supervision or regulatory status for this substance.
What the registries record it as
The substance registry classes this as chemical.
FDA substance registry · 5H7I2IP58X · read 2026-08-29
Its recorded molecular formula is C19H26O2, weighing 286.4.
PubChem record · 13308 · 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.
The limit a reviewer approved as the one that matters most here.
The four opening statements run to 137 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.
Levator ani, prostate and seminal vesicle weight against testosterone propionate at equimolar dose, with AR binding and transactivation in vitro
✓ The study showed what it set out to show
Who was studied
Friedel 2006 rat characterisation of 1-testosterone, the 5alpha-reduced metabolite
How many people
0
Study design
Preclinical, castrated male rats, Hershberger assay
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Equipotent with testosterone propionate on all three organ weights; significant increase in liver weight not seen with testosterone propionate
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. 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. Intramuscular oil-based injection of boldenone undecylenate; no oral form of consequence
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
Boldenone
What a person takes: Intramuscular oil-based injection of boldenone undecylenate; no oral form of consequence.
The measurement behind this step
A viscous oil solution given by deep intramuscular injection. The undecylenate ester makes the depot long-acting, which is the reason for its popularity and also the reason the detection window runs to months. Seizure analyses find these ampoules frequently misfilled, under-dosed or containing an entirely different steroid.
Getting in
Injected as an ester in oil and released over weeks
The drug is attached to a long fatty chain and dissolved in oil, so one injection keeps releasing it for a long time rather than all at once.
──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
Boldenone undecylenate is an 11-carbon ester in an oil vehicle. Depot release from the intramuscular site is slow and rate-limiting; plasma and tissue esterases hydrolyse the ester to free boldenone. The long tail is also why detection windows after the last injection are measured in months rather than days.
Diffuses into the cell to reach a receptor that lives inside
The androgen receptor sits inside cells, not on their surface, so the steroid has to cross the membrane first.
──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
Passive diffusion across the plasma membrane; free boldenone binds the ligand-binding domain of the androgen receptor, displacing heat-shock chaperone complexes and permitting nuclear translocation.
Reduction makes something stronger than the parent
In tissues rich in the reducing enzyme, boldenone is converted into 1-testosterone, which binds the receptor harder than boldenone does.
╌╌Measured in animals. A result in animals says what to test next. It does not say what happens in people.
The measurement behind this step
5-alpha-reductase converts boldenone to 17beta-hydroxy-5alpha-androst-1-en-3-one (1-testosterone). Where testosterone is amplified to dihydrotestosterone, boldenone is amplified to 1-testosterone, a compound shown to bind AR with high selectivity and to match testosterone propionate on androgenic and anabolic endpoints in the rat.
The receptor carries the steroid into the nucleus and turns on the genes that build muscle protein.
╌╌Measured in animals. A result in animals says what to test next. It does not say what happens in people.
The measurement behind this step
Ligand-bound AR dimerises, binds androgen response elements and drives transcription in myonuclei, with parallel activity in prostate and hepatic tissue. The hepatic component is the one that distinguished 1-testosterone from testosterone propionate in the rat assay, where liver weight rose significantly.
Anabolic effect assumed; only the analytical chemistry is measured
What is genuinely documented about boldenone in people is how to detect it, not what it does to them.
──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
There is no human efficacy or safety trial of boldenone. The published human literature is doping-control analytical chemistry — metabolite profiles, detection windows, carbon isotope ratios — plus animal toxicology showing cardiac oxidative injury and troponin I gene dysregulation in rats. The anabolic claim in humans is an extrapolation from receptor pharmacology and from the wider anabolic steroid literature.
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.
Veterinarians treating horses, where it is a licensed product. Outside that, men using it in long injectable courses because the undecylenate ester keeps blood levels up for weeks, and because it has a reputation for causing less water retention than testosterone.
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
Beta-boldenone sulphate was proposed as the unambiguous biomarker of illicit treatment in cattle and did not survive testing against untreated animals, surviving only for samples collected at slaughter
Boldenone was never developed for human medicine and has no completed human trial of any phase
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
Intramuscular oil-based injection of boldenone undecylenate; no oral form of consequence
✎ 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
A viscous oil solution given by deep intramuscular injection. The undecylenate ester makes the depot long-acting, which is the reason for its popularity and also the reason the detection window runs to months. Seizure analyses find these ampoules frequently misfilled, under-dosed or containing an entirely different steroid.
✎ 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
No human safety dataset exists. Documented animal findings include cardiac oxidative injury with increased NOX2 and NOX4 expression and dysregulated troponin I gene expression in rats. The class-level effects expected from any androgen receptor agonist — suppression of endogenous testosterone and gonadotropins by negative feedback, reduced HDL cholesterol, erythrocytosis — have not been quantified for boldenone specifically in humans. The liver-weight signal seen with its 5alpha-reduced metabolite in rats has no human counterpart measurement.
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.
Boldenone appears in spontaneous reports to regulators. Across the 1 most-reported reaction terms, 5 reaction mentions were counted. One report can name several reactions.
The recorded terms (1)
drug abuse — 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
Intramuscular oil-based injection of boldenone undecylenate; no oral form of consequence
✎ 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
The undecylenate ester makes the depot long-acting, which is the reason for its popularity and also the reason the detection window runs to months. Seizure analyses find these ampoules frequently misfilled, under-dosed or containing an entirely different steroid.
✎ 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
1 marketed supplement label lists this ingredient, classed as non-nutrient/non-botanical.
Those labels carry all other 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.
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 Boldenone 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 boldenone aromatises about half as much as testosterone in humans — a structural argument with no human oestradiol measurement supporting 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.
✗Goes past the evidence
That a detected boldenone residue proves administration, which the untreated-bull and equine-metabolism data specifically contradict
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 veterinary licence implies a characterised human safety profile; the licensed species is the horse and the dossier behind it is a veterinary one
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 an ampoule labelled boldenone undecylenate contains boldenone undecylenate, which in seizure analyses is the minority case
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 Boldenone 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.
Its 5-alpha-reduced metabolite is as androgenic as testosterone propionate
In plain words
When the body reduces boldenone it produces 1-testosterone. In a rat assay, an equal dose of 1-testosterone grew the prostate, seminal vesicles and muscle as much as testosterone did — and, unlike testosterone, it enlarged the liver.
What was measured
Levator ani, prostate and seminal vesicle weight and liver weight in the rat Hershberger assay, equimolar against testosterone propionate
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Friedel et al. characterised 17beta-hydroxy-5alpha-androst-1-en-3-one, the 5alpha-reduced product of boldenone, sold on its own as a prohormone. It bound the androgen receptor with high selectivity and strongly stimulated AR-dependent transactivation. In vivo an equimolar dose had the same potency as testosterone propionate at stimulating growth of the prostate, the seminal vesicles and the androgen-sensitive levator ani muscle. Administration of 1-testosterone, in contrast to testosterone propionate, produced a significant increase in liver weight. The authors conclude it is a typical anabolic steroid without needing further metabolism. This is the closest thing to a pharmacological characterisation boldenone has, and it is an animal study of a metabolite.
Written into the record, not signed off as a reviewed claim
Boldenone in bull urine stopped being proof of treatment
In plain words
European residue control treated the active form of boldenone in cattle urine as evidence of illegal hormone use. Then a study of 56 untreated bulls found it in most of them.
What was measured
Frequency of beta-boldenone sulphate (78%) and glucuronide (46%) in urine from untreated young bulls at the farm
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Administration of boldenone to bovines has been banned in the EU since 1981. Alpha-boldenone conjugates were accepted as pseudoendogenous and tolerated up to 2 ng/mL, while conjugated beta-boldenone — the anabolically active epimer — was required to be absent, making it the candidate biomarker of illicit treatment. Chiesa et al. sampled urine from 56 young bulls under official veterinary control for five months, under non-stress conditions, after transport stress, and after slaughter stress. In untreated animals at the farm, beta-boldenone sulphate was found in 78% and the glucuronide in 46%. Detection was inversely related to stress and absent at the slaughterhouse. Histopathology of the bulbourethral and prostate glands showed no significant lesions. The authors conclude the metabolites were of endogenous origin and that beta-boldenone sulphate can serve as a treatment biomarker only in samples taken at slaughter.
Written into the record, not signed off as a reviewed claim
Nearly half of human doping samples with boldenone had an endogenous carbon signature
In plain words
Carbon isotope testing can tell steroid the body made from steroid made in a factory. Of 23 human doping samples containing boldenone, 11 carried the signature of the body, not the factory.
What was measured
13C/12C ratio of urinary boldenone and 5beta-androst-1-en-17beta-ol-3-one against endogenous reference compounds, 23 samples
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Piper et al. developed a GC/C/IRMS method measuring 13C/12C ratios of boldenone, its main metabolite 5beta-androst-1-en-17beta-ol-3-one, and the endogenous reference steroids pregnanediol, androsterone, etiocholanolone and testosterone from a single urine specimen. Validity was established on urine fortified at 2-50 ng/mL. Of 23 doping control samples investigated over four years, 11 gave 13C/12C ratios inconsistent with an exogenous origin. Two of those came from the same athlete a month apart, which the authors read as strong evidence of endogenous boldenone production in that individual. Boldenone is on the WADA prohibited list and has never been approved for human clinical use, so the false-positive risk is not a theoretical concern.
Written into the record, not signed off as a reviewed claim
Horses make boldenone out of testosterone
In plain words
Equine drug testing found that boldenone appears as a minor breakdown product of the horse own testosterone, which is a problem for a sport that bans it.
What was measured
Boldenone identified as a minor metabolite of administered testosterone in equine urine
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Wong et al. presented evidence that boldenone, nandrolone, 5(10)-estrene-3beta,17alpha-diol and 4-estrene-3,17-dione occur as minor metabolites of testosterone in the horse. Separately, Decloedt et al. used an in vitro simulation of the equine hindgut to show that microbial conversion of dietary phytosterols contributes to the excretion of anabolic-androgenic steroids in horses. Both findings point the same way: in the species boldenone is actually licensed for, a positive test can arise from the animal metabolism or its feed. The population-threshold approach used for cattle in the UK, in which characteristic metabolite concentrations in untreated steers and heifers are used to set statistical confirmation thresholds, exists because of exactly this problem.
Written into the record, not signed off as a reviewed claim
Fewer than one in five seized doping products contained what the label said
In plain words
Swiss customs handed 1,190 seized doping products to an anti-doping laboratory. Under 20% contained the labelled substance in the labelled amount.
What was measured
Proportion of seized doping products whose analysed content matched the label: under 20% of 1,190 Swiss items; 4 of 54 French AAS products
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Weber et al. analysed 1,190 products seized at the Swiss border by liquid chromatography-high resolution mass spectrometry, gel electrophoresis with in-gel tryptic digestion for peptides, and electrochemiluminescence immunoassay. Labels claimed anabolic agents for 889 items (75%), peptide hormones or growth factors for 146 (12%), and antioestrogens, aromatase inhibitors or other metabolic modulators for 113 (9%). Non-approved substances were detected, and fewer than 20% of products contained the claimed substance in the claimed amount. Fabresse et al. reached the same conclusion on a smaller French seizure set: of 54 seized products containing anabolic-androgenic steroids, only 4 (7.4%) matched their label qualitatively and quantitatively, and 43 of 54 (80%) were non-original — 33% substandard in dose and 32% outright counterfeit in composition.
Written into the record, not signed off as a reviewed claim
The "less oestrogenic than testosterone" claim rests on no human measurement
In plain words
Boldenone is described as converting to oestrogen at about half the rate of testosterone. No published human study has measured that.
What was measured
That boldenone aromatises at roughly half the rate of testosterone in humans — a structural inference with no human serum oestradiol measurement behind it
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The reputation of boldenone as a low-oestrogen anabolic comes from the structural argument that the 1,2 double bond hinders aromatase and from in vitro comparisons, not from any trial that measured serum oestradiol in people given boldenone. There is no published human pharmacokinetic study, no dose-ranging study and no controlled efficacy study of boldenone for any endpoint in any population. What is documented in animals is toxicity: boldenone undecylenate produced cardiac injury in rats through NADPH oxidase activation with increased NOX2 and NOX4 expression, and chronic administration dysregulated cardiac troponin I gene expression alongside inflammatory-cytokine-driven oxidative stress. Those are rat findings and this page does not extrapolate a human incidence from them.
This order is fixed in code and does not count clicks or time on the page.
What is not here
8 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.
How this medicine reached us — 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
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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 veterinary anabolic steroid with no human trial literature at all, whose 5-alpha-reduced metabolite was measured to be as androgenic as testosterone propionate, and whose defining analytical problem is that untreated bulls, horses and some athletes excrete it endogenously.
Recorded evidence blocks (1)
Q1
What do 5 spontaneous reports say about Boldenone — 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.
Boldenone appears in spontaneous reports to regulators. Across the 1 most-reported reaction term, 5 reaction mentions were counted: drug abuse 5. open-targets-adr · CHEMBL2106059 · 2026-06-24
Show the evidence
drug abuse
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: 1 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.