Educational reference only. Informational material drawn from peer-reviewed literature. Not medical advice and not a recommendation to use, dose, or modify any therapy. Decisions about hormone therapy should be made with a qualified healthcare provider.
Overview
Overview
Oxymetholone is a synthetic anabolic-androgenic steroid (AAS), best known by the trade name Anadrol-50. It is one of the most potent oral anabolic compounds ever developed and is the defining example of 17α-alkylated oral steroid hepatotoxicity in the AAS class. Oxymetholone is FDA-approved for the treatment of anemias caused by deficient red cell production, including aplastic anemia, congenital aplastic anemia (such as Fanconi anemia), myelofibrosis, and hypoplastic anemias from myelotoxic drug administration.
The compound was first synthesized in 1959 by Syntex Corporation and remains in clinical use today, although its applications have narrowed substantially since the development of recombinant erythropoietin in 1989. It has been extensively studied in HIV-related wasting, though now largely superseded by other treatments for that indication.
Unlike most AAS, oxymetholone is not administered as an ester: it is an orally bioavailable compound that does not require ester modification. The 17α-methyl group is what allows oral bioavailability (by protecting from first-pass hepatic metabolism), but this same modification is the basis of the severe hepatotoxicity that characterizes the compound.
Forms
Available forms & half-lives
| Form | Approximate half-life |
|---|---|
| Oxymetholone (oral tablet, not esterified) | ~8–9 hours |
What it does
Main effects
- Dramatic weight gain: rapid increases in body weight (combination of lean mass, water retention, and red cell mass) characterize the compound's clinical and non-medical use profile
- Pronounced muscle and strength gains: among the most potent oral anabolic compounds; effects develop rapidly
- Marked stimulation of erythropoiesis: the basis of the FDA-approved indication for aplastic anemia and other bone marrow failure conditions
- Orally bioavailable without injection: the 17α-methyl modification allows oral dosing (which is also the source of the hepatotoxicity)
- Significant water retention: via paradoxical estrogenic mechanism (not aromatization); contributes to muscle fullness but also to blood pressure and cardiac workload
What to watch for
Common side effects
- Severe hepatotoxicity: the defining safety concern; includes cholestatic jaundice, peliosis hepatis (blood-filled hepatic cysts that can rupture), hepatic adenomas, and hepatocellular carcinoma PMID: 11440282; not rare, sometimes fatal, sometimes irreversible
- Dramatic lipid changes: HDL reductions of 30–50% and pronounced LDL elevations; among the most severe lipid effects of any AAS
- Profound HPG axis suppression
- Paradoxical estrogenic effects: water retention, gynecomastia, mood effects despite NOT being aromatized; mechanism likely involves direct estrogen receptor activity; aromatase inhibitors are typically ineffective; gynecomastia is a marker to discuss with a qualified healthcare provider
- Severe acne and androgenic skin effects: among the more pronounced of any AAS
- Pronounced erythrocytosis: a marker to monitor and discuss with a qualified healthcare provider
- Significant blood pressure elevation: combination of erythrocytosis, water retention, direct vascular effects
- Rapid, often irreversible virilization in women: voice deepening, clitoral enlargement; the Anadrol-50 prescribing information specifically cautions against female use
- Scalp hair loss in genetically predisposed users: 5α-reductase inhibitors do not protect (oxymetholone is already 5α-reduced)
- Cumulative oral-stack hepatotoxicity risk: combining with other 17α-alkylated orals (dianabol, stanozolol, methylated testosterone) produces additive hepatic injury
Key facts
Key facts worth knowing
- Oxymetholone is 17α-alkylated, the specific chemical modification (a methyl group at the C17α position) that allows oral bioavailability but produces significant hepatotoxicity. This is the same modification present in oral compounds like methyltestosterone, stanozolol (Winstrol), and dianabol, but oxymetholone is often considered the most hepatotoxic of commonly used oral AAS.
- The most serious hepatic adverse effects include cholestatic jaundice, peliosis hepatis (blood-filled cysts in the liver that can rupture), and hepatocellular carcinoma with prolonged use. These have been documented in case reports and clinical trials. PMID: 11440282
- The compound's mechanism is distinctive among AAS: it produces dramatic increases in red blood cell production, body weight, and strength, but with significant water retention. Notably, oxymetholone produces estrogenic effects despite NOT being aromatized to estrogen. The mechanism remains incompletely characterized but is hypothesized to involve direct estrogen receptor activity by the parent compound or its metabolites.
- Hengge et al. (1996) demonstrated significant weight gain in HIV-infected patients with advanced disease. Subsequent RCTs in HIV wasting confirmed efficacy but also highlighted the hepatotoxicity profile. Hengge UR et al., Br J Nutrition 1996
- The risk-benefit calculation for oxymetholone is fundamentally different from non-17α-alkylated AAS. The hepatotoxicity is not a rare or hypothetical risk: it is the dominant safety concern that has shaped the compound's clinical use boundaries for decades.
Legal status
Legal status
Schedule III controlled substance in the United States (DEA). FDA-approved as Anadrol-50 for treatment of anemias. WADA-prohibited at all times in competitive sport.