Mastebolin is Alpha Pharma's ampoule presentation of drostanolone propionate: ten 1 ml ampoules of oil solution at 100 mg/ml in a printed carton.
Drostanolone is an injectable androgen derived from DHT. It does not interact with aromatase at all, so no estrogen is formed from it, and the propionate ester attached to it is short-acting, measured in days rather than weeks. Alpha Pharma cartons carry a scratch-off authentication code that can be checked against the manufacturer's own verification page, which is part of why the brand is so widely recognised.
