Drostanolone Propionate (Masteron)
A DHT-derived, non-aromatising injectable (2-alpha-methyl-dihydrotestosterone) historically used to treat breast cancer for its anti-oestrogenic effect. In bodybuilding it is valued for a hard, dry, defined look near contest time rather than raw mass, with a short propionate ester requiring frequent injection. Androgenic side effects (hair loss, acne) predominate; oestrogenic effects are essentially absent.
01 Overview
Drostanolone is dihydrotestosterone with a 2-alpha-methyl group that increases anabolic potency and metabolic stability. It was marketed as Masteron/Drolban for metastatic breast cancer, exploiting its ability to compete with oestrogen at breast tissue — a genuine but dated clinical use, which anchors a modest research score. Modern use is cosmetic: it does not aromatise and produces no water retention, giving a dry, grainy appearance most noticeable in already-lean individuals.
Because it is a potent DHT derivative, its side-effect profile is androgenic — accelerated male-pattern hair loss in the predisposed, acne, and oily skin — rather than oestrogenic. It has a mild anti-oestrogenic action that can complement aromatising compounds. The propionate ester is short, so injections are typically every other day.
02 Mechanism
Androgen-receptor agonist derived from DHT; the 2-alpha-methyl group resists metabolism and it cannot aromatise, so it exerts androgenic and mild anti-oestrogenic effects without oestrogenic water retention.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common | 300–400 mg/wk | IM | Injected every other day due to short ester. |
| Heavy | 400–500 mg/wk | IM | Most effective in already-lean physiques. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Hardening / dry, defined lookReported to increase muscular definition and 'grain' at low body fat; a cosmetic effect not captured in clinical trials. | Anecdotal | ||
| Mild anti-oestrogenic effectHistorically used against oestrogen-sensitive breast cancer; can modestly blunt oestrogenic effects of other compounds. | Clinical | ||
| Preserved lean mass in a deficitPopular in cutting phases to retain muscle and fullness. | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Accelerated male-pattern hair lossAs a potent DHT derivative it can hasten scalp hair loss in genetically predisposed users. | Moderate | Common | Observational | |
| Acne and oily skinAndrogenic stimulation of sebaceous glands. | Mild | Common | Observational | |
| HPTA suppressionSuppresses endogenous testosterone production. | Severe | Universal | Observational |