F tier · safety concern
A never-approved designer steroid distributed through the dietary supplement channel whose published human record consists of cholestatic liver injury case reports, including one with total bilirubin reaching 45.9 mg/dL, alongside a single small doping-control metabolite study.
methylstenbolone
Methylstenbolone is a 17alpha-alkylated dihydrotestosterone derivative marketed through the dietary supplement channel as M-Sten, Ultradrol and as a component of multi-ingredient products such as Super DMZ Rx 2.0. Published human experience is limited to case reports of severe, protracted cholestatic jaundice and to a small doping-control study characterising its urinary metabolites.
the explanation
Methylstenbolone was sold in muscle-building supplements even though it had never been approved as a medicine. Published medical cases describe healthy young men who developed severe jaundice that took months to clear after taking products containing it.
regulatory status
Not individually enumerated in the US Schedule III anabolic steroid list; no approved medical indication has ever existed; sold as an OTC 'prohormone' dietary supplement
Methylstenbolone has never held a marketing authorisation anywhere. It was distributed as a dietary supplement ingredient under names including M-Sten and Ultradrol and inside multi-ingredient products such as Super DMZ Rx 2.0. Unlike methasterone, methylstenbolone does not appear as its own numbered entry in 21 CFR 1308.13(f) — the closest listed compounds are stenbolone at (f)(82) and 17alpha-methyl-delta-1-dihydrotestosterone at (f)(60) — but the Designer Anabolic Steroid Control Act of 2014 extended the CSA anabolic steroid definition to substances structurally substantially similar to listed steroids, and FDA treats anabolic steroids as unlawful dietary ingredients rendering such products adulterated. Anabolic steroids as a class are Class C under the UK Misuse of Drugs Act 1971; prohibited at all times in sport under WADA.
how it works · proposed mechanism
Methylstenbolone is an orally active, non-aromatisable androgen receptor agonist built on the same alkylation strategy that drives oral steroid hepatotoxicity.
C17alpha methyl for oral survival
Methylation at C17alpha blocks hepatic oxidation of the 17beta-hydroxyl, allowing the compound to survive first pass. LiverTox identifies this modification as the defining structural determinant of cholestatic injury among oral androgens, and the published case reports match that phenotype.
2-methyl delta-1 A-ring
The 2-methyl substituent on a delta-1 unsaturated, 5alpha-saturated A-ring resists 3-keto reduction and precludes aromatisation. The result is a metabolically stable, purely androgenic receptor signal with no oestrogenic metabolite.
Canalicular cholestasis phenotype
Liver biopsy in the published case describes canalicular and hepatocellular cholestasis with increased pigmented macrophages, indicating impaired bile export rather than hepatocyte necrosis. This accounts for extreme bilirubin elevation alongside comparatively modest transaminase rise.
what’s reported
evidence shape
6 sourcesThe composition of the cited literature by study type. This describes the shape of the evidence, not its quality — and it does not by itself set the grade.
⚠ the catch
Methylstenbolone reached consumers through a supplement channel that required no toxicology, no dose-finding and no adverse-event reporting, so the only human data that exist were generated either by doping-control chemists or by hepatology units admitting jaundiced patients. Its absence from the enumerated Schedule III list is a drafting artefact rather than a safety signal, and it does not make the compound lawful to sell as a supplement.
key published findings
- Human case report (Agbenyefia P, Arnold CA, Kirkpatrick R, J Investig Med High Impact Case Rep 2014;2(2)): a previously healthy 26-year-old man who took Super DMZ Rx 2.0 (10 mg methylstenbolone plus 10 mg dymethazine per capsule) for 30 days developed dark urine at about three weeks and jaundice by week four.
- Human case report, same case: peak ALT 269 IU/L and AST 154 IU/L on day 35, with total bilirubin peaking at 45.9 mg/dL (direct 25.8 mg/dL) on day 59 — the classic disproportionate cholestatic pattern; biopsy showed canalicular and hepatocellular cholestasis with increased pigmented macrophages; bilirubin fell to 2.1 mg/dL only around 10 weeks after discontinuation.
- Human administration study (Cavalcanti GA et al., Steroids 2013;78(2):228-233): after a single dose in four volunteers, two glucuroconjugated urinary metabolites remained detectable by GC-MS/MS for around one week, whereas unchanged methylstenbolone was detectable for only about 45 hours.
- Human case report (Medical Journal of Clinical Trials and Case Studies, 2018): additional published hepatotoxicity associated with methylstenbolone and stanozolol abuse, reinforcing the case-report signal.
- Regulatory analysis (21 CFR 1308.13(f)): methylstenbolone is not individually enumerated in the Schedule III anabolic steroid list, though stenbolone (f)(82) and 17alpha-methyl-delta-1-dihydrotestosterone (f)(60) are, and the 2014 DASCA structural-similarity provisions extend the definition.
limitations of the evidence
- Human evidence rests on individual case reports plus a single four-volunteer doping-control study; incidence, dose-response and population risk cannot be estimated.
- The best-characterised case involved a two-ingredient product also containing dymethazine, so hepatotoxicity cannot be attributed to methylstenbolone in isolation.
- No pharmacokinetic parameters have been published; the 45-hour figure is a urinary detection window from a doping-control assay, not an elimination half-life, and half-life is reported as null.
documented safety signals
- Severe cholestatic jaundice is the principal documented hazard: total bilirubin reached 45.9 mg/dL in the published case, roughly forty times the upper limit of normal, with only modest ALT/AST elevation.
- Very slow resolution: bilirubin continued to climb for weeks after the product was stopped, peaking on day 59, and had not normalised until roughly ten weeks after discontinuation — stopping the compound does not promptly reverse the injury.
- Prolonged deep cholestasis carries downstream risks including pruritus, fat-soluble vitamin malabsorption, coagulopathy and, in severe androgen-associated cases across this class, acute kidney injury.
- C17alpha alkylation places methylstenbolone in the structural class LiverTox associates with peliosis hepatis, hepatic adenoma and hepatocellular carcinoma on prolonged exposure, with tumour latency typically 5-15 years.
- Marked HDL cholesterol suppression is expected from a 17alpha-alkylated non-aromatisable androgen, with no oestrogenic counterbalance to the atherogenic lipid shift.
- HPG-axis suppression: suppressed LH and FSH, reduced endogenous testosterone, testicular atrophy and impaired spermatogenesis, with uncertain recovery.
- Virilisation in women, including potentially irreversible voice deepening, hirsutism and clitoral enlargement; premature epiphyseal closure with exposure before skeletal maturity.
- Supplement-channel hazards compound the pharmacology: products were sold without dose verification or purity control, frequently stacked multiple undeclared designer steroids in one capsule, and carried no adverse-event surveillance.
- Regulatory ambiguity has been actively exploited in marketing; absence of an individual CSA entry has been misrepresented as evidence of safety or legality, which it is not.
identity
| full name | Methylstenbolone (2,17alpha-dimethyl-17beta-hydroxy-5alpha-androst-1-en-3-one) |
| category | Anabolic & Androgenic |
| modality | steroid |
| formula | C21H32O2 |
| molar mass | 316.5 g/mol |
| cas | 6176-38-1 |
laboratory handling
| storage | Solid; store tightly closed, protected from light and moisture at controlled room temperature; certified reference solutions are supplied and stored refrigerated or frozen in acetonitrile. |
| solubility | Practically insoluble in water; soluble in ethanol, methanol, acetonitrile and DMSO. Analytical standards are commonly distributed as acetonitrile solutions. |
Handling information describes laboratory practice for a research reagent. It is not a preparation guide for use in humans.
the receipts
6 citedFederal Register (DEA) · 2023 · official
PubChem, US National Library of Medicine · 2026 · official
NIDDK / NCBI Bookshelf · 2020 · review
Journal of Investigative Medicine High Impact Case Reports · 2014 · observational
Steroids · 2013 · observational
Medical Journal of Clinical Trials and Case Studies · 2018 · observational
others in Anabolic & Androgenic