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Methenolone (Primobolan) Research

Mostly mechanism / observational

7 peer-reviewed studies

What the evidence says

Mostly mechanism / observational

Most Methenolone (Primobolan) studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.

Most evidence is from mixed-quality randomised trials published 1968–2024 with a typical study size of 39 participants.

Based on 7 studies · 2 RCTs · 111 total participants

Confidence

Low confidence

By outcome

Anemia & hematology
Too few graded studies2 studies
Lean mass & anabolic effectA mild anabolic-androgenic steroid (Primobolan) with modest lean-mass/anti-catabolic effects; adverse cholesterol shifts and HPTA suppression. A controlled substance. · Not established for physique use
Too few graded studies2 studies
Androgenic & hormonal effects
Too few graded studies2 studies
Safety profile
Too few graded studies2 studies
Cholesterol & lipids
Too few graded studies1 study

Steady research

1 study in the last 5 years

196819962024

1RCT1971

Kollmeier H, Müller HO · Arzneimittelforschung (1971)

No plain-language summary recorded for this citation — open the paper to read its abstract.

2RCT1968

Kennedy BJ, Yarbro JW · Cancer (1968)

No plain-language summary recorded for this citation — open the paper to read its abstract.

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3Observationaln=39 · small study2007

In plain English: Favorable responses were achieved in 17 patients (44%, 8 good and 9 minimum responses)... anabolic steroids are well tolerated and effective for the treatment of anemia in a subset of MMM patients.

Shimoda K, Shide K, Kamezaki K, Okamura T, Harada N, Kinukawa N, Ohyashiki K, Niho Y, Mizoguchi H, Omine M, Ozawa K, et al. · International journal of hematology (2007)

The best available clinical evidence for the historical anemia use — a retrospective analysis of 39 patients with myelofibrosis with myeloid metaplasia treated with anabolic steroids (including methenolone) in Japan
Favourable hemoglobin responses (≥1.5 g/dL rise and/or transfusion independence) in 44% of patients; adverse events were described as moderate and transient
Observational, not randomized — it grounds the erythropoiesis/anemia mechanism in real patients but is retrospective, and only some patients received methenolone specifically

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4In Vitro1984

In plain English: RBAs relative to that of MT: MT greater than 19-nortestosterone (nandrolone) greater than methenolone (17 beta-hydroxy-1-methyl-5 alpha-androst-1-en-3-one) greater than testosterone (T) greater than 1 alpha-methyl-DHT.

Saartok T, Dahlberg E, Gustafsson JA · Endocrinology (1984)

The mechanistic anchor: an in-vitro receptor-binding study comparing anabolic-androgenic steroids' affinity for the androgen receptor in skeletal muscle and prostate and for sex-hormone-binding globulin
Methenolone bound the muscle/prostate androgen receptor more strongly than testosterone but below methyltrienolone and nandrolone, and bound SHBG more weakly than DHT — characterizing it as a genuine but moderate-affinity androgen
Provides the in-vitro pharmacology underlying methenolone's androgenic/anabolic action and its comparative mildness

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5Observationaln=28 · very small study1981

In plain English: In ten women hyperlipoproteinaemia type IIa was demonstrated in the course of treatment, while in two there was hyperlipoproteinaemia type IIb. One of the latter patients had a myocardial infarction in the course of treatment.

Garbrecht M, Lehmann U, O'Brien S, Stolzenbach G, Müllerleile U · Deutsche medizinische Wochenschrift (1981)

The mandatory counter-evidence on harm: an observational study of 28 menopausal women given additive methenolone enanthate during breast-cancer treatment, examining its effect on lipid metabolism
Hyperlipoproteinaemia developed in 12 of 28 women on treatment, and one patient with type-IIb hyperlipoproteinaemia had a myocardial infarction during therapy
The hyperlipoproteinaemia regressed once methenolone was discontinued, and showed no dose relationship — a reversible but real adverse lipid signal

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6Observationaln=43 · small study1975

In plain English: Objective remissions lasting longer than 3 months occurred in 8 out of 41 evaluable patients... The therapeutic efficiency of Primobolan Depot is comparable to that of testosterone propionate but the agent is less virilising.

Notter G · Acta radiologica: therapy, physics, biology (1975)

The historical oncology indication: a case series of 43 women with disseminated/inoperable breast carcinoma treated with methenolone enanthate (Primobolan Depot) 400–1200 mg/week for at least 3 months
Objective remissions >3 months in 8 of 41 evaluable patients; soft-tissue metastases responded best, while liver and brain metastases were unaffected
Efficacy reported as comparable to testosterone propionate but less virilizing — an early observation of methenolone's comparative mildness as an androgen

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7Case Studyn=1 · very small study2024

In plain English: He was treated with methenolone acetate and darbepoetin for anemia caused by myelodysplastic syndrome. During anemia treatment, the decline in bone mineral density was attenuated over time.

Ushimaru S, Sumi H, Aso M, Fujishima R, Shiizaki K, Tominaga N · JCEM case reports (2024)

A contemporary (2024) single case report — an older man with stage-4 chronic kidney disease and myelodysplastic syndrome treated with methenolone acetate plus darbepoetin for the anemia of MDS
Documents methenolone acetate (the oral form) still in use for marrow-failure anemia, and an incidental attenuation of bone-mineral-density decline during treatment
Lowest tier of evidence (n=1, no control), included to show the anemia indication persists in modern practice and the kind of case-level data that is the bulk of methenolone's recent literature

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View in Research Library

Methenolone (Primobolan) Research

Mostly mechanism / observational

[Reduction of alpha-2-globulins following administration of 1-methyl-delta-1-androstenolone enonthate].

Effect of methenolone enanthate (NSC-64967) in advanced cancer of the breast.

The effect of anabolic steroids on anemia in myelofibrosis with myeloid metaplasia: retrospective analysis of 39 patients in Japan.

Relative binding affinity of anabolic-androgenic steroids: comparison of the binding to the androgen receptors in skeletal muscle and in prostate, as well as to sex hormone-binding globulin.

[Hyperlipoproteinaemia during additional methenolone administration in the treatment of metastasizing carcinoma of the breast].

Treatment of disseminated carcinoma of the breast by metenolone enanthate.

Attenuation of Bone Mineral Density Decline During Anemia Treatment With Methenolone Acetate in Myelodysplastic Syndrome.