Methasterone (Superdrol)

Methasterone — most people know it by the designer-supplement name Superdrol, and chemists call it methyldrostanolone — is a man-made anabolic-androgenic steroid (AAS), not a peptide. It is an oral steroid built on a dihydrotestosterone backbone, with a chemical tweak called 17α-alkylation that lets it survive being swallowed. Syntex first made it in the 1950s, but it was never approved as a medicine. It later showed up as an over-the-counter “supplement” in the mid-2000s before being made a controlled substance. Here is the key point: nobody has ever tested its muscle-building claims in a proper human trial. The strongest human evidence we do have is about harm — serious liver damage in young men who were healthy beforehand.

What it is

Methasterone is a synthetic, orally active anabolic-androgenic steroid (CAS 3381-88-2). Chemically it is a relative of dihydrotestosterone (DHT, a potent natural androgen) — its full name is 2α,17α-dimethyl-17β-hydroxy-5α-androstan-3-one. Compared with testosterone, it has a few structural differences: it is missing one of testosterone’s double bonds (it has a 5α-reduced, DHT-type “A-ring”), and it carries two extra methyl groups, one at the 2α position and one at the 17α position. The simplest way to picture it: it is drostanolone with an added 17α-methyl group. That 2α-methyl group makes it more anabolic (more muscle-building) and helps it resist being broken down by an enzyme called 3α-HSD. The 17α-alkylation is what lets it survive first-pass liver metabolism (the liver’s first attempt to break down anything you swallow), so it works as a pill rather than an injection.

How does it work? Like other AAS, it switches on the androgen receptor (AR) — the cell’s docking point for male hormones. Once switched on, the receptor turns up genes that build muscle protein and add lean mass. Because it is a 5α-reduced DHT derivative, it is not a target for aromatase (the enzyme that turns androgens into estrogen), so it cannot convert directly into estradiol (the main form of estrogen). The original Syntex research described it as strongly muscle-building with relatively weak androgenic (masculinizing) effects. But not converting to estrogen does not protect users from gynecomastia (breast tissue growth in men) — see Safety.

The claims

Methasterone has no approved medical use anywhere. Historically, it only drew laboratory interest in anabolic and anti-tumor screening. In athletic and bodybuilding circles, people use it illicitly or off-label to gain lean mass, build strength, and “recomp” (lose fat while gaining muscle), usually during a cutting or lean-bulk phase. Its appeal is that it is a pill and does not convert to estrogen.

What the evidence actually shows

There are no controlled human trials testing whether methasterone works. Because it was never a clinical drug, the claims about lean mass and strength rest on old animal and lab-dish (in-vitro) screening data from the Syntex era, plus personal anecdotes — not on randomized human studies. So the evidence for its performance and physique claims is very weak and essentially uncontrolled.

The only solid human medical literature is about harm — a clear, well-documented pattern of severe cholestatic liver injury (a type of liver damage where bile backs up and is not cleared properly) in young men who were healthy before using Superdrol/methasteron:

• Shah et al., 2008 — a report on 5 patients with methasteron-linked cholestatic liver injury. Jaundice (yellowing of the skin and eyes) showed up about 2 weeks after they stopped, bilirubin (the pigment that builds up when the liver cannot clear bile) peaked over the next 2–3 weeks, and all 5 eventually recovered (about 12 weeks) with no lasting liver damage and without needing a transplant.
• Kafrouni, Anders & Verma, 2007 — 2 young men with significant cholestatic injury from dietary supplements that contained anabolic steroids; both recovered without a transplant.
• Jasiurkowski et al., 2006 — Superdrol-induced cholestatic jaundice plus IgA nephropathy (a kidney condition), a notable case that ties the drug to kidney trouble as well.
• Nasr & Ahmad, 2009 — severe cholestasis with kidney failure blamed on Superdrol/methasteron, along with a review of the published literature.

The NIH LiverTox monograph on Androgenic Steroids discusses Superdrol/methasteron among the C17-alkylated androgens that cause “bland cholestasis” (bile backup without much obvious cell damage). It also lays out the wider range of liver problems linked to 17α-alkylated steroids: brief rises in liver enzymes (transaminases), bland cholestasis, peliosis hepatis (blood-filled cysts or spaces in the liver), and liver tumors (adenomas and hepatocellular carcinoma, usually after years of use).

Legal and regulatory status

In the United States, methasterone is a Schedule III controlled substance. Anabolic steroids are Schedule III under the Anabolic Steroid Control Act (part of the Controlled Substances Act). Methasterone specifically was scheduled by a DEA Final Rule published July 30, 2012 (effective August 29, 2012), where it was classified — alongside prostanozol — as a Schedule III anabolic steroid. It was later named among the substances covered by the Designer Anabolic Steroid Control Act of 2014 (DASCA, signed December 18, 2014), which broadened the legal definition of “anabolic steroid” and named specific compounds. The DEA’s rule putting that into practice followed (published August 1, 2023, updating the regulatory list to cover all variations of the chemical names of methasterone and prostanozol). The bottom line: methasterone is federally controlled (Schedule III) and can no longer be legally sold as a supplement.

In sport, methasterone (methyldrostanolone) is banned at all times — both in and out of competition — under WADA Class S1 (Anabolic Agents), specifically S1.1 (Anabolic Androgenic Steroids), where it is listed as a named example. The 2026 Prohibited List, in force as of 1 January 2026, also makes clear that esters (chemically attached fatty-acid versions) and compounds with a similar structure or effect are banned too. (For context: clenbuterol sits under S1.2, “Other Anabolic Agents,” and is also banned at all times — but that subgroup does not apply to methasterone, which is an actual steroid and therefore falls under S1.1.)

Safety

Methasterone carries the full risk profile of an oral 17α-alkylated androgen, and its standout documented harm in humans is liver injury.

• Hepatotoxicity (the signature risk): As a 17α-alkylated oral steroid, methasterone is hard on the liver. The documented human pattern is cholestatic jaundice — fatigue, itching (pruritus), dark urine, and a sharp rise in bilirubin (reported in one case well above 40 mg/dL), often with only modest rises in the liver markers ALT and ALP. It tends to appear during use or 1–2 months afterward, sometimes getting worse after stopping before it clears over weeks to months. With longer use, this class of drug also carries the risk of peliosis hepatis and liver tumors.
• Renal (kidney): Case reports document acute kidney injury / kidney failure and IgA nephropathy (a kidney disease), sometimes alongside the liver problems.
• Cardiovascular / lipids: Like other oral 17α-alkylated AAS, it is expected to push cholesterol in a harmful direction (sharply lowering HDL, the “good” cholesterol, and raising LDL, the “bad” one) and is tied to the general AAS heart-risk profile (high blood pressure, changes to heart structure, and dyslipidemia-driven risk of clogged arteries). There are no heart studies on this specific compound in humans; this risk is judged from the broader steroid class.
• HPTA suppression / fertility: It shuts down the hypothalamic-pituitary-testicular axis (the body’s hormone control loop for making testosterone). This lowers the body’s own testosterone and the signaling hormones LH and FSH, and leads to shrunken testicles, impaired sperm production, and possible infertility — which may last for a while after stopping.
• Gynecomastia: Breast tissue can still grow in men even though the drug does not convert to estrogen, because it suppresses the body’s own testosterone and throws off the androgen-to-estrogen balance.
• Virilization (in women): Masculinizing effects including a deeper voice, extra body hair (hirsutism), disrupted periods, and clitoral enlargement — some of which do not reverse.
• Hematologic (blood): A steroid-class effect of raised hematocrit (thicker blood from more red cells), which increases the risk of clots.
• Other steroid-class effects: Acne, hair loss (androgenic alopecia), and mood or aggression changes; in teenagers, use risks premature epiphyseal closure (bones stop growing early).

A note on the evidence grade: the efficacy claims (lean mass and strength) are not backed by controlled human trials — they come from old animal anabolic screening and anecdote (very low confidence). The strongest, repeatedly confirmed human evidence is about harm, especially cholestatic liver damage. By design, no doses, cycles, stacks, or PCT protocols are included here.

Bottom line

Methasterone (Superdrol) is a synthetic oral anabolic-androgenic steroid — a 17α-methylated version of drostanolone — that was made in the 1950s, never approved as a medicine, and briefly sold as a “supplement” before being scheduled. Its muscle-building claims have never been tested in controlled human trials. The only solid human evidence about it documents serious harm, most notably severe cholestatic liver injury in otherwise healthy young men, plus added risks to the kidneys, heart, and hormones, and the other usual steroid risks. It is a federally controlled Schedule III substance and is banned at all times in sport. It is an anabolic steroid, not a peptide.

Evidence grade: 3/10 · Animal only.

Sources

• Shah NL et al. 2008 — methasteron-associated cholestatic liver injury, 5 cases (PMID 18187367)
• Kafrouni MI, Anders RA, Verma S 2007 — hepatotoxicity from anabolic-steroid dietary supplements (PMID 17509944)
• Jasiurkowski B et al. 2006 — cholestatic jaundice and IgA nephropathy from Superdrol (PMID 16952289)
• Nasr J, Ahmad J 2009 — severe cholestasis and renal failure with Superdrol/methasteron (PMID 18720005)
• NIH LiverTox — Androgenic Steroids (discusses methasteron/Superdrol)
• DEA Final Rule 2012 — Prostanozol and Methasterone scheduled as Schedule III (Federal Register, July 30, 2012)
• DEA — Implementation of the Designer Anabolic Steroid Control Act of 2014 (Federal Register, August 1, 2023)
• WADA — The 2026 Prohibited List (methasterone under S1.1 Anabolic Androgenic Steroids)
• Methasterone — overview, chemistry, and history (Syntex origin; drostanolone/Masteron parent)