Masteron

A DHT-derived injectable with a historical role as a breast-cancer drug (as dromostanolone). Modern non-medical use occurs in physique-sport settings.

Drostanolone (Masteron) is a derivative of dihydrotestosterone, which is the fact that shapes everything about it: DHT derivatives cannot be converted to oestrogen, so it produces no water retention and no oestrogenic breast effects. That is the source of its reputation for a dry, hard look, which is a user report rather than a controlled finding. It is also strongly androgenic at the sites DHT acts on — scalp, skin, prostate — so what it avoids on the oestrogen side it adds on the androgenic one. It was historically used in advanced breast cancer, which is where its limited human record comes from. Injectable anabolic-androgenic steroids share a structural point: an ester chain attached to the molecule controls how slowly it releases from the injection site, which sets how long it acts. The ester is not the drug — it is cleaved off — but it determines how long anything, including any adverse effect and any suppression, persists after the last injection.

Real oncology history, zero physique-use trials. Every claim about its cosmetic effect is community anecdote without a controlled measurement behind it.

• NONE SHOWN for physique use. Its human record is historical oncology use in advanced breast cancer, an entirely different context, population and purpose.
• The cosmetic "hardening" effect that drives its use is user report, and the visible change is substantially the absence of water retention rather than added tissue.
• Its mild reputation rests on the absence of oestrogenic effects, not on any demonstrated safety advantage.
• Androgenic effects — accelerated hair loss in the predisposed, acne, prostate effects — are the predictable consequence of a DHT derivative and are consistently reported.
• It is prohibited in tested sport.

Available with short and long esters that differ substantially in how long they release and therefore how long effects and suppression persist. As a DHT derivative it does not aromatise at all, and finasteride does not block it in the usual way because it is already 5-alpha reduced. No FDA-approved human product exists for this use; illicit product identity and sterility are unverifiable.

Strong androgenic pressure — hair loss and acne are heavily reported — plus lipid damage, HPG-axis suppression, and cardiovascular strain. In practice it is usually taken alongside other AAS, so real-world exposure is rarely to this drug alone.

• Class-level severe outcomes reported with anabolic steroids, which no compound here is exempt from: cardiac arrest, heart attack, thickened heart muscle, heart failure and stroke; serious liver injury; and mania, paranoia, psychosis, hostility, aggression, dependence and depression on withdrawal.
• Pregnancy and breastfeeding: androgens can cause fetal harm including virilisation of a female fetus. Avoid in both.
• Anyone predisposed to male pattern hair loss, where a DHT derivative accelerates it
• Anyone with prostate cancer, significant prostate symptoms, or male breast cancer
• Anyone with unfavourable lipids or cardiovascular disease
• Women, given virilisation risk including irreversible voice change
• Anyone who wants children in the foreseeable future

• Anticoagulants, which anabolic steroids can potentiate.
• Tell whoever manages your lipids that you are using it. Nothing here is a reason to start, stop or change a prescribed medicine.
• Hair loss on a DHT-derived compound needs a clinician rather than a self-selected drug — adding medicines to manage steroid effects is unapproved and can create its own harm.
• Tested sport, where it is prohibited.

• Full lipid panel — non-aromatising steroids tend to be harder on lipids, since oestrogen contributes to a favourable HDL.
• Blood pressure and haematocrit.
• Total and free testosterone, LH and FSH.
• Prostate symptoms, and PSA where age-appropriate — this is a potent androgen with no oestrogen conversion.
• Scalp and skin, where androgenic effects show first in those predisposed.

The dry appearance reverses as water balance normalises, which people often read as losing more than they have. Endocrine recovery after anabolic-steroid use is variable, can take months and can be incomplete, with no reliable individual prognosis. Androgenic hair loss accelerated during use does not reverse when the compound stops.

US: Schedule III anabolic steroid under the CSA. No current US pharmaceutical production.

Papers about this compound, not proof of the claims above. A title says what was studied, which is sometimes a negative result or a different question entirely.

• Comparison of testosterone decanoate, drostanolone and testololactone in disseminated breast cancer--a randomized clinical study
  Arch Geschwulstforsch, 1975
• Androgen therapy of incurable breast neoplasms. Controlled clinical study: nandrolone-testololactone-drostanolone
  Onkologie, 1978
• A comparison of drostanolone propionate (Masteril) and nandrolone decanoate (Deca-durabolin) in the treatment of breast carcinoma
  Clin Oncol, 1976

• Exploring the Polymorphism of Drostanolone PropionateMolecules · 2020
• New drostanolone metabolites in human urine by liquid chromatography time-of-flight tandem mass spectrometry and their application for doping controlSteroids · 2016
• Seven new metabolites of drostanolone heptanoate by using Beauveria bassiana, and Macrophomina phaseolina cell suspension culturesRSC Adv · 2019
• Drostanolone and norethisterone in disseminated breast cancerDrug Ther Bull · 1969
• Searching for new long-term urinary metabolites of metenolone and drostanolone using gas chromatography-mass spectrometry with a focus on non-hydrolysed sulfatesDrug Test Anal · 2020
• Treatment of advanced breast carcinoma with drostanolone propionate. A case reportBristol Med Chir J · 1970
• [Drostanolone propionate (masteril) in disseminated breast cancer in women. Immediate results]Khirurgiia (Sofiia) · 1987
• Effect of drostanolone propionate on the binding of oestradiol and dihydrotestosterone by normal and malignant target tissuesEur J Cancer (1965) · 1977
• Identification of drostanolone and 17-methyldrostanolone metabolites produced by cryopreserved human hepatocytesSteroids · 2009
• Intracerebroventricular self-administration of commonly abused anabolic-androgenic steroids in male hamsters (Mesocricetus auratus): nandrolone, drostanolone, oxymetholone, and stanozololBehav Neurosci · 2005
• Comparison of testosterone decanoate, drostanolone and testololactone in disseminated breast cancer--a randomized clinical studyArch Geschwulstforsch · 1975
• [Experiences with Drostanolone-Propionate (Masterid) in metastasizing breast carcinoma]Ther Ggw · 1972