Description
Mesterolone (Proviron) is an oral dihydrotestosterone derivative with 1-methyl modification that makes the substance orally effective without a 17α-methyl group. The missing 17-alkylation is an important safety feature - Proviron is not hepatotoxic in the classical sense.
Per study reports Mesterolone binds with high affinity to the androgen receptor but has practically no anabolic action with oral administration. The central effects are: strong binding to SHBG with displacement of testosterone (raising the free fraction of test), weak anti-estrogen action at the estrogen receptor and androgenic residual action.
In clinical endocrinology Proviron is used for treatment of male hypogonadism, fertility problems and libido decrease. The substance is approved as a prescription medication in many countries.
In recreational research practice Proviron has three clear use cases: 25-50mg/day in cycles for SHBG lowering (more bioavailable test), as mild E2 accompaniment in E2-borderline research setups and in cutting phases for the DHT-mediated “hardness” effect.
Pharmacokinetically orally bioavailable with about 12-13 hour half-life. Bioavailability is around 3% (very low due to missing 17α-methyl group), but the high SHBG displacement effect makes this disadvantage practically irrelevant per study reports.
Known effects are mild compared to classical anabolics: HPG suppression documented but lower than under Anavar, lipid profile worsening moderate, no significant hepatotoxicity.
You can order Mesterolone as oral tablets in one bottle with 25mg per tablet.
This information is for research and educational purposes only. No medical recommendations.
Risks & Safety
Mesterolone has a comparatively mild risk profile and differs substantially from the classical oral anabolics - it is not 17α-methylated and not hepatotoxic in the classical sense. The effects documented in the literature are milder than under alkylated orals.
Documented in studies and the user literature:
- No relevant liver strain: due to the missing 17α-methyl group, Mesterolone is described in the literature as not significantly hepatotoxic.
- Lipid profile: a moderate unfavorable shift of the lipid profile is documented in studies.
- Suppression of natural production: HPG suppression is described in the literature, lower than under Anavar, but present.
- Androgenic effects: as a DHT derivative, androgenic residual effects such as accelerated hair loss in genetically predisposed individuals are described in the literature.
This classification does not replace medical advice. Risk and responsibility for any actual use lie entirely with the buyer.
Studies
- The effect of mesterolone administration to normal men on the pituitary-testicular function - Acta Endocrinologica 1974, Aakvaag et al: clinical endocrine study documenting significant HPG suppression and lowered total testosterone with stable free testosterone under 75-150mg/day mesterolone.
- 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 - Endocrinology 1984, Saartok et al: reference study on AR and SHBG binding affinities, finding mesterolone has roughly four-fold higher SHBG affinity than DHT.
- Double-blind group comparative study of testosterone undecanoate and mesterolone in hypogonadal male patients - Journal of Endocrinological Investigation 1980: comparative trial in hypogonadal men on oral testosterone undecanoate versus mesterolone.
- A clinical and endocrine study of mesterolone in secondary impotence - Journal of Psychosomatic Research 1980: clinical and endocrine investigation of mesterolone in secondary impotence, documenting effects on libido and endocrine markers.
- A pilot study of mesterolone in impotence - Psychopharmacologia 1972: early placebo-controlled pilot study on mesterolone effects in male sexual dysfunction.
