Masteron (Drostanolone) — DHT-Derivative AAS — Anabolic Steroids
DHT-derivative anabolic steroid historically FDA-approved for breast cancer, now used primarily in bodybuilding for its anti-estrogenic and hardening effects.
Overview
Drostanolone (Masteron) is a dihydrotestosterone (DHT) derivative anabolic steroid that was first described in 1959 and introduced for medical use in 1961. It was FDA-approved under the brand name Masteron for the treatment of inoperable breast cancer in postmenopausal women, where it provided anti-estrogenic effects through competitive inhibition of aromatase activity. As a DHT derivative, drostanolone cannot be aromatized to estrogen, and it possesses inherent anti-estrogenic properties by competing with estrogens for binding at the aromatase enzyme complex. The medical use of drostanolone has been largely discontinued in favor of modern aromatase inhibitors and SERMs. In bodybuilding, Masteron is prized for its 'hardening' effects on physique appearance, moderate anabolic activity (anabolic:androgenic ratio ~62:25), and anti-estrogenic properties that reduce water retention. It is available as drostanolone propionate (short-acting, every other day injection) and drostanolone enanthate (long-acting, weekly injection). Masteron does not cause significant hepatotoxicity as it is not 17-alpha-alkylated. However, being a potent DHT derivative, it accelerates male pattern baldness, can cause acne, and may enlarge the prostate.
Indications
- Historically FDA-approved: Inoperable breast cancer in postmenopausal women (discontinued)
- Unapproved: Physique hardening and water reduction (bodybuilding use)
- Unapproved: Anti-estrogenic adjunct during steroid cycles
Mechanism of Action
Binds the androgen receptor with moderate affinity, producing anabolic effects in muscle with strong androgenic activity
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Drostanolone Propionate | 100 mg | Every other day | Short ester; common bodybuilding dose |
| Drostanolone Enanthate | 200-400 mg | Once weekly | Long ester; less frequent injection |
Evidence Grade
GRADE C
Safety & Contraindications
- Accelerates androgenetic alopecia (hair loss) — potent DHT derivative
- Acne and oily skin common
- Prostate enlargement risk
- HPG axis suppression
- Lipid changes: HDL depression, LDL elevation
- Virilization risk in women (deepening voice, hirsutism)
- Schedule III controlled substance
- Not hepatotoxic (not 17-alpha-alkylated)