Buy 99.1% Purity USP Bulk Raw Steroids Drostanolone Propionate / Masteron Propionate Powder Online CAS 521-12-0  What is Drostanolone Propionate? Masteron (CAS No.: 521-12-0) is an injectable oil-based anabolic steroid, and is derived from Dihydrotestosterone (DHT), which makes Masteron a member of the DHT-derived family of anabolic steroid derivatives and analogues. Masteron is not regarded as a very strong anabolic steroid …