Dianabol

Methandienone (also called methandrostenolone, trade name Dianabol) is a synthetic anabolic-androgenic steroid (AAS) structurally derived from testosterone. It carries a 17α-methyl group and an added 1,2-double bond in the steroid ring system, giving it a distinct anabolic-to-androgenic activity profile compared with testosterone itself.

The 17α-methyl modification is the key structural feature responsible for its oral bioavailability. This alkyl group at carbon-17 slows hepatic first-pass metabolism, allowing meaningful amounts of the compound to reach systemic circulation after ingestion. As a result, methandienone became one of the earliest widely used oral anabolic steroids in clinical and, later, athletic contexts.

Human study: A double-blind crossover trial in seven male weight-lifters found significant increases in body weight, total body potassium, total body nitrogen, muscle size, and leg performance during training on methandienone compared with placebo. The authors noted the ratio of potassium to nitrogen gain was inconsistent with normal lean tissue, suggesting the weight gained was not ordinary muscle. (PMID 7018798)

Human study: A double-blind crossover study in 11 athletic men showed that methandienone was associated with greater weight gain (mean 3.3 kg) and disproportionately large potassium accumulation compared with placebo, with muscle size increasing. Strength and performance improved over each training period but not significantly more on the drug than on placebo. (PMID 61389)

Human study: In the same study of 11 athletic men, plasma cortisol concentration and urinary cortisol excretion increased while plasma testosterone decreased during methandienone use, indicating notable endocrine effects alongside body-composition changes. (PMID 61389)

Animal study: The rabbit study found that methandienone impairs ovarian steroidogenic activity by downregulating CYP19A1 mRNA expression and promoting oxidative stress, indicating a hormonal disruption mechanism beyond simple androgenic activity. (PMID 41836328)

Laboratory study: In vitro experiments using human liver microsomes showed that several antifungal drugs (itraconazole, ketoconazole, miconazole) and the antidepressant nefazodone significantly reduced formation of hydroxylated and dehydrogenated methandienone metabolites. An in vivo follow-up confirmed that co-administration with ketoconazole altered the urinary metabolic profile of methandienone, potentially complicating doping detection. Note: Doping/detection study; co-administration with ketoconazole examined in vivo in humans and in vitro with human liver microsomes. (PMID 29766657)

Laboratory study: Using uPA+/+-SCID mice engrafted with functional human hepatocytes, researchers identified six of seven known human methandienone metabolites in chimeric mouse urine, closely mirroring human metabolism, whereas control non-humanized mice produced only two. Four metabolite isomers were also detected in both human and chimeric mouse urine, one of which had not been previously reported. Note: Doping/detection study using humanized-liver mouse model to characterize human metabolism. (PMID 19643840)

Human study: A case report described a 19-year-old male who developed rhabdomyolysis and a psychotic episode with homicidal ideation following use of methandrostenolone. The patient had a prior history of cannabis use but no previous psychotic symptoms. Note: Methandrostenolone used in context of poly-substance misuse including cannabis. (PMID 30185243)

Human study: Two young children (ages 2 and 4) who received a syrup containing methandienone and cyproheptadine developed excessive virilization; the 4-year-old boy also developed adrenal insufficiency. Stopping the syrup led to partial regression of virilization and normalization of adrenal function in the boy. Note: Methandienone was present in an off-label appetite-stimulant syrup co-formulated with cyproheptadine. (PMID 19618666)

Human study: A literature review of drug-induced pancreatitis found suggestive but not definitive evidence that methandienone may be associated with pancreatitis. The authors classified it among drugs for which evidence is less convincing but still present. (PMID 3044464)

Animal study: In a controlled study of female rabbits, methandienone administration significantly suppressed ovarian CYP19A1 (aromatase) gene expression and serum oestrogen levels compared with controls, and elevated markers of oxidative stress including malondialdehyde and protein carbonyl content. Selenium supplementation partially reversed these effects. (PMID 41836328)

Laboratory study: An environmental monitoring study detected methandienone in wastewater influent and surface water samples from the Pearl River basin in China, and computational biotoxicity modelling predicted methandienone to have the highest acute and chronic aquatic toxicity among the five androgens tested. The authors concluded environmental androgenic risk should not be ignored. Note: Environmental detection study; no administration to humans or animals. (PMID 38085110)

Limitations:

Human study: The authors of the 1981 crossover trial explicitly noted that the previous study had left open the question of whether muscle gains represented normal tissue or intracellular fluid, and that even the follow-up with nitrogen measurements could not fully resolve this, as the potassium-to-nitrogen ratio was atypical for normal lean tissue. The study involved only seven subjects. (PMID 7018798)

Open questions: Several important questions remain unresolved. The clinical studies available are small, older, and used high doses, making it unclear how the body-composition changes observed (increased nitrogen, potassium, and muscle dimensions) translate to real muscle protein accretion versus altered fluid or electrolyte distribution. Whether strength and performance gains reliably exceed those from training alone has not been definitively settled. The long-term cardiovascular, hepatic, and endocrine consequences of even short-term use in humans are poorly characterised by controlled prospective data.

The interaction between methandienone and commonly co-administered medications (including antifungals and antidepressants) can alter its metabolic profile, but the clinical significance of these pharmacokinetic interactions for health outcomes is unknown. Finally, the environmental presence of methandienone in surface and wastewater and its ecological toxicity to aquatic organisms warrant further investigation.