Peptide & Experimental
Drostanolone (Masteron)
Anabolic-androgenic steroid, derivative of dihydrotestosterone (DHT); formerly a medicine for advanced breast cancer · drostanolone propionate, dromostanolone, Masteron, Masteril, Masterid, Drolban, 2α-methyl-dihydrotestosterone
Drostanolone is a derivative of dihydrotestosterone, known in the scene by the trade name Masteron. In the 1960s and 1970s it was used as a medicine for advanced breast cancer; today it is mainly a doping agent from the black market. In humans it has been studied only in tumor therapy – for the purpose for which it is traded today, there is no study.
In short
What holds up: drostanolone is an androgen with a clinical past. In controlled studies from the 1970s in women with metastatic breast cancer, about one in four patients responded to treatment, similar to testosterone decanoate, testolactone or nandrolone. In the US it was approved as Drolban; the approval has been discontinued. Where the data stop: there is not a single human study on muscle mass, strength or body fat in healthy people, and substance-specific safety data are almost entirely missing. The risks are those of anabolic steroids as a class – shutdown of the body’s own hormone production, strain on the heart and blood vessels, unfavorable blood lipids, virilization in women. In Germany, drostanolone is listed in the Anti-Doping Act; in sport it is prohibited at all times.
What drostanolone is
Drostanolone is an anabolic-androgenic steroid and a derivative of dihydrotestosterone (DHT), with an additional methyl group at carbon atom 2. As a medicine it was injected as drostanolone propionate, under trade names such as Masteron, Masteril, Masterid and, in the US, Drolban. It was used mainly in women with advanced, metastatic breast cancer.
In the US, the approval of Drolban is now listed as discontinued; we found no currently approved product either there or in Germany. What is traded as Masteron today does not come from a pharmacy. The page Anabolic steroids gives an overview of the entire substance group.
How it works
Like DHT, drostanolone binds to the androgen receptor. This results in anabolic and virilizing effects and, as with any administered androgen, feedback on the hormonal axis: the body’s own testosterone production is shut down.
As a 5α-reduced androgen, drostanolone is not converted to estrogen; its use in hormone-dependent breast cancer was based on this. Unlike many anabolic steroids in tablet form, it is not alkylated at the 17α position. How strong the anabolic effect is in humans has never been measured.
What is well supported
- Tumor response in breast cancer. In controlled studies from the 1970s, 22 to 25 % of women with metastatic breast cancer responded to hormone therapy alone; drostanolone performed similarly to the comparator drugs.
- A genuine androgen. The effect via the androgen receptor and the shutdown of the body’s own hormonal axis follow from the substance class, which is well studied in humans.
- Former approval. In the US, drostanolone propionate was approved as Drolban; the approval is listed as discontinued.
What the studies show
Rieche and Wolff 1975: three hormones in a randomized comparison
The randomized study compared testosterone decanoate, drostanolone and testolactone in metastatic breast cancer. As hormone therapy alone, all three achieved similar rates of objective tumor response, 22 to 25 %. In a second phase, the chemotherapy drug cyclophosphamide was added; this raised the rate to 46 to 55 %, although drostanolone plus cyclophosphamide performed less favorably than the other two combinations during the observation period of 10 to 16 weeks.
Wolff and Rieche 1978: 91 patients
In a controlled study with 91 patients with advanced breast cancer, testolactone, drostanolone and nandrolone were compared. No difference was found between the three drugs. After 4 weeks, an average of 24 % responded; after a further 12 weeks with additional cyclophosphamide, 46 %.
Choi 1974: blood lipids in dialysis patients
In dialysis patients who took dromostanolone – the American spelling – for their anemia, blood triglycerides rose. It is one of the few substance-specific indications of side effects; details such as the number of cases cannot be verified without the full text.
Where the data stop
- No study on today’s use. There is no human study and no ClinicalTrials.gov entry on muscle mass, strength, body fat or performance in healthy people.
- Old data, different people. The studies date from the 1970s and involved seriously ill women; they cannot be transferred to healthy men in strength sports.
- Hardly any safety data. There is no modern safety study and no pharmacovigilance; the assessment of the risks rests on the data for the entire substance class.
- Products from the gray market. Without an approved product, everything sold as Masteron is untested for content and purity.
Status, approval and legal
We found no currently approved medicine containing drostanolone either in Germany or in the US; the former US approval of Drolban (Eli Lilly) is listed as discontinued. In Germany, finished medicinal products may only be placed on the market with a marketing authorization (§ 21 of the German Medicines Act).
Drostanolone is listed by name in the annex of the German Anti-Doping Act. Manufacturing, trading and placing it on the market for the purpose of doping in sport are prohibited, as are acquisition, possession and bringing it into Germany in more than a small quantity for this purpose; violations are punishable under § 4 with imprisonment of up to three years or a fine. In sport it is prohibited in and out of competition under the WADA Prohibited List 2026 under S1.1, anabolic-androgenic steroids.
Safety
Substance-specific safety data on drostanolone barely exist. A rise in triglycerides in dialysis patients on dromostanolone is documented. Everything else comes from the data on the substance class: administered androgens shut down the body’s own hormonal axis, with reduced fertility, and strain the heart and blood vessels; in addition there are psychological and metabolic effects, and virilization in women. The Endocrine Society describes the widespread assumption that use is safe or manageable as a misjudgment.
On the liver: the typical cholestasis and liver tumors under anabolic steroids have been described mainly for 17α-alkylated steroids; drostanolone is not one of them. Nevertheless, there are no liver data of its own. Anyone having blood values, blood lipids or the heart checked should disclose the use – here, every step should be preceded by a conversation with a doctor, because of consequences that can be lasting.
BK-Score Long used, barely studied
| Human evidence | 3 | |
|---|---|---|
| Mechanism | 7 | |
| Safety data | 3 | |
| Hype gap | 3 | |
| Track record of use | 6 |
Evidence 3, because in humans there are only controlled studies from the 1970s, and these concern tumor response in advanced breast cancer (Rieche and Wolff 1975; Wolff and Rieche 1978 with 91 patients, no difference from testolactone and nandrolone); on muscle mass, strength or body fat in healthy people, the purpose advertised today, there is not a single study, so the direction is open. Mechanism 7, because drostanolone, as a methylated dihydrotestosterone, acts via the androgen receptor and is not converted to estrogen, but its potency and tissue profile in humans have never been measured. Safety 3, because substance-specific safety data are almost absent – a rise in triglycerides in dialysis patients is documented (Choi 1974) –, there is no pharmacovigilance and the risk assessment rests on the class data for anabolic steroids. Hype 3, because the substance is traded in strength sports with promises for which there is no evidence in humans; use 6, because drostanolone was used for years as an approved medicine for breast cancer and has since been widespread outside medicine, but its medical use has been discontinued. For comparison: nandrolone (8/9/9/6/9) as an approved steroid with 60 years of data, anabolic steroids (7/9/6/4/6) for the class, ligandrol (4/6/3/2/4) for a substance with thin human evidence and hardly any safety data.
The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)
Frequently asked questions about drostanolone (Masteron)
What is drostanolone?
Drostanolone, known as Masteron, is an anabolic-androgenic steroid and a derivative of dihydrotestosterone. In the 1960s and 1970s it was used as a medicine for advanced breast cancer in women; today it is mainly a doping agent.
Is the effect on muscle building supported?
No. The only controlled human studies concern tumor response in breast cancer. There is no study on muscle mass, strength or body fat in healthy people; what is said about this rests on anecdotal reports and on the analogy to other anabolic steroids.
Why was drostanolone used in breast cancer?
It acts as an androgen and is not converted to estrogen. In studies from the 1970s in metastatic breast cancer, about one in four patients responded, similar to other androgens.
Is drostanolone legal in Germany?
We did not find an approved medicine. Drostanolone is listed in the annex of the German Anti-Doping Act: trading and passing it on for doping are prohibited, as are acquisition and possession of more than a small quantity for doping in sport. In sport it is prohibited at all times under the WADA list.
What side effects does drostanolone have?
Substance-specific data barely exist; a rise in triglycerides in dialysis patients is documented. Otherwise the risks of anabolic steroids as a class apply: shutdown of the body’s own hormone production with reduced fertility, strain on the heart and blood vessels, psychological effects and, in women, virilization.
Related
- Related topicBoldenone (Equipoise)
- Related topicFluoxymesterone (Halotestin)
- Related topicMethasterone (Superdrol)
- Related topicMethyltrienolone (metribolone, R1881)
- Related topicDHB (1-testosterone, dihydroboldenone)
- Related topicNandrolone decanoate
Sources
- Rieche K, Wolff G, Arch Geschwulstforsch 1975 – randomized comparison of testosterone decanoate, drostanolone and testolactone in metastatic breast cancer
- Wolff G, Rieche K, Onkologie 1978 – controlled study of nandrolone, testolactone and drostanolone, 91 patients
- Choi ES et al., Am J Clin Nutr 1974 – hypertriglyceridemia in dialysis patients on dromostanolone for anemia
- de Boer D et al., J Steroid Biochem Mol Biol 1992 – the methylated dihydrotestosterones mesterolone and drostanolone, urinary excretion
- Drugs@FDA – NDA 012936, Drolban (dromostanolone propionate, Eli Lilly), status discontinued
- Petrovic A et al., World J Gastroenterol 2022 – liver damage caused by anabolic-androgenic steroids (review)
- Pope HG et al., Endocr Rev 2014 – health consequences of performance-enhancing drugs, Endocrine Society scientific statement
- German Medicines Act (Arzneimittelgesetz, AMG), § 21 marketing authorization requirement
- German Anti-Doping Act (Anti-Doping-Gesetz, AntiDopG), § 2, § 4 and annex
- NADA – Prohibited List 2026, informational German translation (S1.1 anabolic-androgenic steroids)
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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-10-05.