Methyl-1-testosterone (M1T) is a synthetic oral anabolic-androgenic steroid (AAS). It is 1-testosterone (the steroid sold as “DHB”) with a methyl group added at carbon 17, the same change that makes methyltestosterone and other oral steroids survive passage through the liver. It has been marketed as a “dietary supplement,” and anti-doping researchers describe it as a designer steroid (Parr et al., Endocrinology 2011).
The single most important fact: M1T has never been an approved medicine and has never been tested in a controlled human trial. What is known comes from one rat study, anti-doping excretion studies in a handful of volunteers, and case reports. Since 2005 it has been a Schedule III controlled substance in the US, and it is banned in sport at all times.
This page summarizes what laboratory studies, case reports and regulators report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Drug class | Synthetic 17α-methylated anabolic-androgenic steroid; 17α-methyl derivative of 1-testosterone |
| Other names | 17α-methyl-1-testosterone; 17β-hydroxy-17α-methyl-5α-androst-1-en-3-one; SC-11195; listed by USP as an oxandrolone impurity (“Δ1-mestalone”) |
| Formula / weight | C₂₀H₃₀O₂, 302.5 g/mol |
| Approval | No approved medical product anywhere we could find; sold as a “supplement” and online |
| Route (as sold) | Oral |
| Human trials | None; human data are limited to urine excretion studies and case reports |
| Half-life | Not reported in humans |
| US status | Schedule III controlled substance (named in the Anabolic Steroid Control Act of 2004) |
| WADA status | Prohibited at all times (S1.1, listed by name) |
What it is
M1T’s chemical name is 17β-hydroxy-17α-methyl-5α-androst-1-en-3-one, formula C₂₀H₃₀O₂, molecular weight 302.5 g/mol (PubChem CID 7092657). PubChem also lists it under the code SC-11195 and as a United States Pharmacopeia reference impurity of oxandrolone, named “Δ1-mestalone.”
It differs from its closest relatives in one or two places:
| Compound | A-ring double bond | 17α-methyl group | Library page |
|---|---|---|---|
| Testosterone | Carbons 4–5 | No | Testosterone cypionate |
| Methyltestosterone | Carbons 4–5 | Yes | Methyltestosterone |
| 1-Testosterone (DHB) | Carbons 1–2, with 5α-hydrogen | No | DHB cypionate |
| Methyl-1-testosterone (M1T) | Carbons 1–2, with 5α-hydrogen | Yes | This page |
The 17α-methyl group slows breakdown in the liver, which is why M1T is taken by mouth. Other oral steroids with the same group include oxandrolone, methandienone and methasterone.
Because M1T is already 5α-reduced and lacks the 4-ene A-ring that aromatase acts on, it would not be expected to convert to estradiol. No study we found measured this in people.
Its parent steroid, 1-testosterone
In a rat study by the same Cologne group, 1-testosterone bound selectively to the androgen receptor and, at an equimolar dose, stimulated the prostate, seminal vesicles and levator ani muscle as strongly as testosterone propionate. Unlike testosterone propionate, it also increased liver weight (Friedel et al., Toxicol Lett 2006). These are animal results. The DHB page covers 1-testosterone in more depth.
How it works in the body
The only study that characterized M1T’s hormonal activity combined a cell-based test, a rat experiment and human urine analysis (Parr et al., Endocrinology 2011):
| Test | What was found |
|---|---|
| Yeast androgen-receptor transactivation assay (in vitro) | M1T acted as a potent androgen |
| Hershberger assay in rats, injected under the skin | Dose-dependent growth of the prostate (androgenic effect) and the levator ani muscle (anabolic effect) |
| Hershberger assay in rats, by mouth | No effect on organ weights, but dose-dependent prostate cell proliferation and changes in IGF-I and androgen-receptor expression in calf muscle |
| Liver marker in rats (tyrosine aminotransferase expression) | Strong activity in the liver, much higher after oral dosing |
The authors concluded that M1T is a potent anabolic and androgenic steroid by both routes, that it shows no selective androgen receptor modulator (SARM)-like tissue selectivity, and that it “might exhibit liver toxicity,” especially when taken by mouth. Rat results do not establish effects or safe doses in people.
Metabolism and detection
No study has reported M1T’s blood levels or half-life in humans. The half-life figures quoted online are not traceable to any measurement we could find.
What is known comes from urine studies done for drug testing:
- Main human metabolites. After administration to humans, unchanged M1T was found in urine together with two main metabolites, 17α-methyl-5α-androst-1-ene-3α,17β-diol and 17α-methyl-5α-androstane-3α,17β-diol, plus their 17-epimers and rearranged 18-nor metabolites (Parr et al., 2011).
- Conjugated metabolites. In a 2025 study, one healthy man took a single 10 mg oral dose and urine was collected for 84 h. The analysis flagged 23 candidate sulfate or glucuronide metabolites for future testing methods (Koomen et al., J Am Soc Mass Spectrom 2025).
- Product identification. A Chinese lab analyzed an oral product containing an unidentified steroid, found it to be M1T, and built a urine test with a detection limit of 2 ng/mL (Qiu et al., Se Pu 2010).
These studies used single doses in one or a few volunteers and were designed to detect the drug, not to assess its effects or safety.
Regulatory status
M1T was never approved as a medicine, so there is no label, no approved indication and no labeled dose.
- United States. The Anabolic Steroid Control Act of 2004 added “17α-methyl-Δ1-dihydrotestosterone (a.k.a. ‘17-α-methyl-1-testosterone’)” to the federal definition of anabolic steroids. The change took effect 90 days after the law was signed on October 22, 2004 (Public Law 108-358). It remains listed as a Schedule III anabolic steroid (21 CFR 1308.13).
- Sport. The WADA 2026 Prohibited List names methyl-1-testosterone under S1.1 anabolic androgenic steroids, prohibited both in and out of competition (WADA 2026 Prohibited List).
What the research shows
No human efficacy data
No controlled trial has given M1T to people to measure muscle, strength, body composition or any medical outcome. Claims about how much muscle it builds, or how it compares with other steroids, are not supported by published human data.
How common its use is
In an online survey of 2,385 men who used AAS, 137 (5.75%) reported having used methyl-1-testosterone (Bonnecaze et al., Am J Mens Health 2020). The survey was conducted online, and the authors note it may over-represent men who use AAS forums.
Still found in supplements
A 2026 systematic review of undeclared prohibited substances in dietary supplements listed methyl-1-testosterone among the anabolic steroids detected in products sold as supplements (Al-Saad et al., Front Sports Act Living 2026). A buyer of a “supplement” may therefore take M1T without knowing it, which matters both for health and for anti-doping tests.
Side effects and risks
There are no trial-based side-effect rates for M1T. The risks below come from the rat study, a published case, and what is known about the class of designer steroids sold as supplements.
Liver
In rats, M1T showed strong activity in the liver, much higher after oral dosing, and the authors warned of possible liver toxicity (Parr et al., 2011). Across designer steroids sold over the counter, reported severe effects include liver toxicity, cholestasis (blocked bile flow, which causes jaundice and itching), kidney failure, hypogonadism, gynecomastia and infertility (Rahnema et al., Andrology 2015).
Interaction with ciclosporin: a case report
A 29-year-old man with severe atopic dermatitis had been stable on ciclosporin (an immunosuppressant) for 4 months. He then started an oral M1T product bought online and developed acute kidney injury (Al-Niaimi & Lyon, Dermatol Ther 2013):
| Measure | Baseline | After starting M1T | Normal range |
|---|---|---|---|
| Creatinine | 93 µmol/L | 266 µmol/L | 59–104 µmol/L |
| ALT (a liver enzyme) | 31 IU/L | 304 U/L | 0–45 IU/L |
| Bilirubin | 12 µmol/L | 37 µmol/L | 1–25 µmol/L |
His trough ciclosporin level was markedly elevated despite an unchanged dose. Kidney and liver tests returned to normal within a week of stopping both drugs. The authors proposed that M1T impaired the liver’s handling of ciclosporin, either by competing for cytochrome P450 enzymes or by reducing bile flow. This is a single case, so it shows a possible interaction rather than how often it happens.
Hormonal suppression and other class effects
No study has measured M1T’s effect on LH, FSH or natural testosterone in people. Because it is a potent androgen in laboratory tests, the usual AAS effects would be expected, including suppression of the body’s own testosterone and sperm production. Designer-steroid supplements as a group have been linked to hypogonadism and infertility (Rahnema et al., 2015).
Who should be especially cautious
- People taking drugs with a narrow safety margin that are cleared by the liver, such as ciclosporin, based on the case above.
- People with existing liver disease, given the rat liver findings and the liver injury reported with designer-steroid supplements.
- Athletes in tested sport, since M1T is prohibited at all times and also turns up in products labeled as supplements.
Key takeaways
- A methylated form of 1-testosterone. M1T is 1-testosterone (DHB) with a 17α-methyl group, which makes it orally active.
- Never a medicine. There is no approved product, label or labeled dose, and no controlled human trial of its effects.
- Potent androgen in the lab. In cells and in rats it acted as a strong anabolic and androgenic steroid without SARM-like selectivity, with marked activity in the rat liver after oral dosing.
- Half-life unknown. Human data are limited to urine excretion studies after single doses; no blood half-life has been published.
- Documented harm is case-level. A published case linked M1T to kidney injury through an interaction with ciclosporin, and designer-steroid supplements as a class have caused cholestatic liver injury.
- Controlled and banned. Schedule III in the US since 2005, and prohibited at all times under the WADA 2026 list.
Sources
- Parr MK, Blatt C, Zierau O, et al. Endocrine characterization of the designer steroid methyl-1-testosterone: investigations on tissue-specific anabolic-androgenic potency, side effects, and metabolism. Endocrinology. 2011;152(12):4718–4728. PubMed.
- Friedel A, Geyer H, Kamber M, et al. 17beta-hydroxy-5alpha-androst-1-en-3-one (1-testosterone) is a potent androgen with anabolic properties. Toxicol Lett. 2006;165(2):149–155. PubMed.
- National Center for Biotechnology Information. PubChem Compound Summary for CID 7092657, Methyl-1-testosterone. PubChem.
- Koomen DC, Leaptrot KL, May JC, et al. Rapid annotation strategy for in vivo phase II metabolites of anabolic-androgenic steroids using liquid chromatography-ion mobility-mass spectrometry. J Am Soc Mass Spectrom. 2025;36(8):1762–1770. PubMed.
- Qiu L, Shangguan L, Liu W, et al. Component analysis of a new anabolic androgenic steroid and its monitoring research in human urine [in Chinese]. Se Pu. 2010;28(1):49–53. PubMed.
- Anabolic Steroid Control Act of 2004. Public Law 108-358, 118 Stat. 1661 (October 22, 2004). govinfo.
- Schedules of controlled substances: Schedule III. 21 CFR 1308.13. eCFR.
- World Anti-Doping Agency. The 2026 Prohibited List: International Standard. In effect January 1, 2026. WADA 2026 Prohibited List.
- Bonnecaze AK, O’Connor T, Aloi JA. Characteristics and attitudes of men using anabolic androgenic steroids (AAS): a survey of 2385 men. Am J Mens Health. 2020;14(6):1557988320966536. PubMed; PMC.
- Al-Saad N, Aljaal S, Alessa J, et al. Systematic review of undeclared prohibited substances and pharmacological adulterants in dietary supplements: prevalence, detection, and risks in sport. Front Sports Act Living. 2026;8:1740663. PubMed.
- Rahnema CD, Crosnoe LE, Kim ED. Designer steroids - over-the-counter supplements and their androgenic component: review of an increasing problem. Andrology. 2015;3(2):150–155. PubMed.
- Al-Niaimi F, Lyon CC. Acute kidney injury due to interaction of methyl-1-testosterone with ciclosporin metabolism in a patient with severe atopic dermatitis. Dermatol Ther (Heidelb). 2013;3(2):211–214. PubMed; PMC.