HALOTESTIN

Fluoxymesterone was introduced in the late 1950s as a potent oral androgen for hypogonadism and advanced breast carcinoma. Clinical studies confirmed detectable urinary metabolites for at least 5 days after a single 10 mg oral dose, with primary metabolism via 6β-hydroxylation, 4-ene-reduction, 3-keto-reduction, and 11-hydroxy-oxidation. Its use in oncology (e.g., VATH regimen for refractory breast cancer) showed meaningful response rates. However, its 17α-alkylated structure confers significant hepatotoxicity, and clinical guidelines explicitly advise against long-term oral androgen therapy due to liver damage risk. Evidence for performance enhancement is largely anecdotal and from illicit use; controlled trials in athletes are lacking.