Nandrolone and Turinabol Interaction: Avoid | Peptide Database

Join others researching Masteron — share findings, ask questions, and learn from real experiences Masteron (drostanolone) is a synthetic dihydrotestosterone (DHT)-derived anabolic-androgenic steroid originally developed and marketed as Masteril and Drostanolone Propionate for the treatment of inoperable breast cancer in postmenopausal women. It received FDA approval for this indication in the 1970s but has since been discontinued from pharmaceutical markets. Structurally, drostanolone is DHT with a 2-alpha-methyl group, which increases its anabolic potency and protects it from metabolic breakdown by 3-alpha-hydroxysteroid dehydrogenase in muscle tissue. As a DHT derivative, Masteron does not aromatize to estrogen and exhibits mild anti-estrogenic properties, likely through competitive inhibition at the aromatase enzyme or direct antagonism at the estrogen receptor. This makes it uniquely suited for cutting and contest preparation cycles where a dry, hard, and grainy physique is desired. Masteron is not a mass-building compound; its primary value lies in aesthetic enhancement, estrogen management, and synergy with other anabolic agents. It is available in two ester forms: the short-acting propionate (original pharmaceutical form) and the longer-acting enanthate (underground lab formulation). Effective results are most visible at lower body fat percentages, typically below 12-15%, where its hardening and drying effects become pronounced. Drostanolone binds to the androgen receptor with high affinity, promoting protein synthesis and nitrogen retention in skeletal muscle. As a DHT derivative, it cannot be converted to estrogen by the aromatase enzyme, eliminating estrogen-related side effects such as water retention and gynecomastia from the compound itself. Masteron exhibits anti-estrogenic activity through a dual mechanism: it competitively inhibits aromatase enzyme activity (reducing conversion of other aromatizable steroids like testosterone to estradiol) and may act as a weak antagonist at estrogen receptors in breast tissue, which was the basis for its historical use in breast cancer treatment. This anti-estrogenic property is the reason Masteron can reduce or eliminate the need for dedicated aromatase inhibitors when stacked with testosterone. Unlike testosterone, drostanolone is not a substrate for 5-alpha reductase, as it is already a DHT derivative and cannot be further reduced. This means its full androgenic potency is expressed in all tissues, including hair follicles and the prostate, which accounts for its significant hair loss potential in genetically predisposed individuals. The 2-alpha-methyl modification prevents inactivation by 3-alpha-hydroxysteroid dehydrogenase in muscle, allowing drostanolone to exert its full anabolic effect at the tissue level rather than being rapidly metabolized to inactive forms as unmodified DHT would be.

The original 2017 mouse study used 5 mg/kg IP, 3 times on alternate days. For a 60kg human, this translates to approximately 25mg per dose, administered as 3 doses every other day (75-100mg total per cycle). However, human pharmacokinetics differ significantly from mice, making these translations speculative.