Methandrostenolone (Dianabol)

Methandrostenolone — known around the world as metandienone or methandienone, and by the brand name Dianabol — is one of the most famous anabolic-androgenic steroids ever made (a class of muscle-building drugs based on the hormone testosterone). It is a lab-made cousin of testosterone, not a peptide, and it was the classic “oral bulking steroid” of mid-20th-century bodybuilding. What sets it apart from most performance drugs is that it was actually tested in proper human trials in the 1970s and 1980s — the gold-standard kind, where neither the subjects nor the researchers knew who got the real drug versus a dummy pill. That means we can talk about its real effects instead of relying on gym rumors. This page sums up that evidence, where it stands legally, and its serious safety risks. It contains no doses, cycles, stacks, or protocols.

What it is

Methandrostenolone is a man-made anabolic-androgenic steroid (AAS) — a tweaked version of testosterone. Its chemical name is 17α-methyl-17β-hydroxyandrost-1,4-dien-3-one (in plain terms, testosterone with an extra methyl group bolted on at one spot and a small change to its ring structure). The names methandrostenolone, metandienone, methandienone, and Dianabol all point to the same single molecule.

Like other steroids in its class, it works by switching on the androgen receptor (AR) — the cellular docking point that testosterone normally uses. Flipping that switch tells the body to build muscle (more muscle protein made, more nitrogen held onto), along with the typical masculinizing (“androgenic”) effects. The body can also convert it through a process called aromatization into estrogen-like byproducts, which is part of why it can cause breast tissue growth and water retention.

The standout feature of its design is 17α-alkylation — that extra methyl group mentioned above. It slows down how fast the liver breaks the drug down on the first pass through, which is exactly what lets the drug work when swallowed as a pill. The catch is that this same feature is what makes pills like this hard on the liver (more on that under Safety). This is the big difference from injectable steroids such as testosterone esters, which don’t have this modification and don’t damage the liver the same way.

The claims

The non-medical pitch for methandrostenolone is simple: fast gains in body weight, lean/muscle mass, and strength. That is why it has long been sold as an oral “kickstart” drug in bodybuilding. Back when it was a medicine, the claims matched what doctors of that era used it for — building up the body and restoring weight in conditions like osteoporosis (weak, brittle bones) and growth problems. Today there is no legitimate US medical use, and using it for performance is both illegal (Schedule III) and banned in sport.

What the evidence actually shows

The best human data come from two carefully run trials in trained men by Hervey and colleagues. Both were double-blind and placebo-controlled (neither side knew who got the drug), with each man taking turns on both the drug and the dummy pill:

• Hervey et al., Lancet 1976 (PMID 61389): the men gained body weight, and that gain was all lean (not fat). Their muscles got bigger, and they held onto an unusually large amount of potassium. Importantly, strength and performance improved during each training period, but there was no clear difference between the drug and the placebo. While on the drug, the stress hormone cortisol went up and natural testosterone went down.
• Hervey et al., Clin Sci 1981 (PMID 7018798): body weight, total-body potassium and nitrogen, muscle size, and leg strength/performance all went up meaningfully on the drug but not on the placebo. The authors added a caution: the mix of nitrogen and potassium the men gained didn’t look like normal muscle, hinting that the “muscle building” measured on paper probably overstated how much real, working muscle was actually added.

Put together, the best controlled evidence supports real gains in body weight and lean mass / muscle size when the drug is combined with training. The strength benefit was modest, and in these small trials it was hard to separate from the effect of the training itself. Much bigger and cleaner proof that high-dose androgens raise muscle size and strength comes from the controlled testosterone research (Bhasin et al., NEJM 1996, PMID 8637535) — that applies to the steroid class as a whole, but it is a different molecule, so it backs up the picture rather than being direct evidence about methandrostenolone. Older bodybuilding-era reports are mostly uncontrolled and anecdotal (based on personal stories, not careful experiments).

In short: the class effect of anabolic steroids on muscle is solidly proven in humans, and methandrostenolone specifically has placebo-controlled data showing lean-mass gains — which is why it earns a strong human evidence grade for its headline muscle-building effect. The honest caveat is that its standalone strength benefit in these trials was smaller and less certain than its gym reputation suggests.

Legal and regulatory status

• Anabolic steroids are Schedule III controlled substances in the US, placed there by the Anabolic Steroids Control Act of 1990 (Pub. L. 101-647), which amended the Controlled Substances Act. The drug is named outright in the legal definition of “anabolic steroid” at 21 U.S.C. § 802(41) as “methandienone (17α-methyl-17β-hydroxyandrost-1,4-dien-3-one)” — that is methandrostenolone itself.
• The list was widened and updated by the Anabolic Steroid Control Act of 2004 (Pub. L. 108-358) and again by the Designer Anabolic Steroid Control Act of 2014; the listed steroids are written into DEA regulations at 21 CFR § 1308.13(f).
• What this means in practice: owning, selling, or importing methandrostenolone without a prescription is a federal crime, and there is no current FDA approval allowing medical use in the US. Any US supply today is illegal or fake.
• Anti-doping (WADA): metandienone is a banned anabolic agent under Category S1 (Anabolic Agents), subsection S1.1 (Anabolic Androgenic Steroids), prohibited at all times (both in and out of competition). It is one of the most commonly caught steroids in drug testing. The 2026 List makes clear that esters of banned anabolic agents are banned too.

(For context across the class: clenbuterol is not FDA-approved for people and is not a scheduled controlled substance, but it is banned in sport under WADA S1.2 “Other Anabolic Agents”; human growth hormone is handled by its own distribution law, 21 U.S.C. § 333(e), rather than the controlled-substance schedules, and falls under WADA S2.)

Safety

• Liver toxicity (the main worry with 17α-alkylated pills): NIH LiverTox lists methandienone/methandrostenolone among the 17α-alkylated androgens tied to four kinds of liver injury: (1) temporary rises in liver enzymes (markers in the blood that signal liver stress); (2) a sudden, often “bland” cholestatic syndrome (where bile backs up in the liver, usually starting within about 1–4 months); (3) peliosis hepatis (blood-filled pockets in the liver that can make it fragile and prone to rupture with longer use); and (4) liver tumors — both adenomas (benign growths) and hepatocellular carcinoma (liver cancer), usually after years of use. The same 17α-alkyl group that lets the drug work as a pill is what drives this damage.
• Heart and cholesterol: oral steroids, especially 17α-alkylated ones, cause big unhealthy shifts in blood fats — large drops in HDL (“good” cholesterol) and rises in LDL (“bad” cholesterol) — and with long-term use are linked to high blood pressure, an enlarged or weakened heart muscle, and a greater tendency to form clots and clog arteries.
• Hormone shutdown and fertility: taking an outside androgen suppresses the body’s own hormone control system (the brain-to-testicle signaling loop), leading to lower natural testosterone, suppressed LH/FSH (the brain signals that tell the testicles to work), shrunken testicles, and reduced or absent sperm production / infertility. Recovery can take a long time and is not guaranteed.
• Estrogen-related effects: because metandienone converts into estrogen-like compounds, it can cause gynecomastia (breast tissue growth in men) and fluid retention/swelling.
• Masculinizing effects (virilization): in women — and in still-growing teens — the androgenic effects include a deeper voice, extra body/facial hair, disrupted periods, and clitoral enlargement, some of which do not reverse — plus, in teens, the growth plates in the bones can close early and stunt height.
• Blood: androgens boost red blood cell production and can raise hematocrit (the share of blood made up of red cells), which increases clot risk.
• Other: acne and oily skin, male-pattern hair loss, mood and behavior changes (irritability, aggression), and psychological dependence have all been reported. Illegal supply adds the dangers of fakes, mislabeling, and contamination.

Bottom line

Methandrostenolone is an oral anabolic-androgenic steroid with a genuine, placebo-controlled evidence base showing it increases body weight and lean mass alongside training — though its standalone effect on strength in those trials was modest. It is not a peptide. In the US it is a Schedule III controlled substance with no legal medical use, it is banned at all times in sport, and it carries serious, well-documented risks to the liver, heart and cholesterol, hormone system, and (in ways that can be permanent) to women and teens. The muscle-building effect is real; so is the harm.

Evidence grade: 9/10 · Strong.

Sources

• Hervey et al. “‘Anabolic’ effects of methandienone in men undergoing athletic training.” Lancet. 1976;2(7988):699-702. PMID 61389.
• Hervey et al. “Effects of methandienone on the performance and body composition of men undergoing athletic training.” Clin Sci (Lond). 1981;60(4):457-461. PMID 7018798.
• Bhasin S, et al. “The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men.” N Engl J Med. 1996;335(1):1-7. PMID 8637535. (Class-level context, not methandrostenolone-specific.)
• NIH LiverTox. “Androgenic Steroids.” Clinical and Research Information on Drug-Induced Liver Injury. NCBI Bookshelf NBK548931.
• 21 U.S.C. § 802 — definition of “anabolic steroid” (methandienone enumerated). Cornell LII.
• 21 CFR § 1308.13 — Schedule III; enumerated anabolic steroids. Cornell LII.
• 21 U.S.C. § 333 — penalties; § 333(e) governs human growth hormone. Cornell LII.
• Anabolic Steroid Control Act of 2004, Pub. L. 108-358 (full text). govinfo.
• WADA 2026 Prohibited List (International Standard, effective 1 Jan 2026).
• WADA 2026 Prohibited List (resource landing page).
• USADA. “Athlete Advisory: What’s New on the 2026 WADA Prohibited List?”
• Metandienone — Wikipedia (background/history aggregation).