Last updated: March 2026
Trestolone (7α-Methyl-19-nortestosterone, MENT) is a Population Council–developed 19-nor steroid originally designed as a male hormonal contraceptive. With ~10× the anabolic potency of testosterone and a unique aromatization to 7α-methylestradiol, its pharmacology requires special monitoring and management strategies.
The 7α-methyl group distinguishes MENT from nandrolone — it prevents 5α-reduction to a weakened metabolite, maintains full androgenic potency throughout metabolism, and creates a unique estrogenic aromatization product not detectable on standard tests.
Regular nandrolone converts via 5α-reductase to dihydronandrolone (DHN) — a weak androgen. Trestolone's 7α-methyl group blocks 5α-reduction, so MENT remains pharmacologically active as MENT throughout the body. This preserves its anabolic activity in tissues where nandrolone would be inactivated. Population Council research identifies this as why MENT is ~10× more potent per milligram.
Unlike trenbolone (no aromatization) or testosterone (aromatizes to standard E2), trestolone aromatizes to 7α-methylestradiol — an estrogen not measured by standard estradiol immunoassays. Standard E2 bloodwork reads near zero while significant estrogenic activity occurs. Aromatase inhibitors (anastrozole, exemestane) do control this conversion. Estrogen monitoring requires LCMS-based testing, not standard immunoassay.
Population Council studies demonstrate that even low doses of MENT (~400mcg/day transdermal) suppress FSH/LH sufficiently to produce near-complete azoospermia (zero sperm) in weeks. Because MENT does not require sperm-suppressing feedback through the same pathway as testosterone, it achieves contraceptive efficacy while maintaining libido and androgenic function — the research objective for which it was developed.
The acetate ester (MENT Acetate) has an ~8-hour half-life, requiring daily or twice-daily subcutaneous injections. This makes blood levels highly dependent on injection timing consistency. A decanoate ester with ~7-day half-life has been studied experimentally. Community research predominantly uses the acetate form. Injection site rotation is important given injection frequency requirements.
Population Council clinical data on contraceptive efficacy, plus community-reported performance data (labeled).
LCMS estradiol testing is critical for trestolone research — standard immunoassay tests are unreliable.
Dosing schedules, interaction warnings, and cycle protocols for 50+ compounds — all in one place.
This page is for educational and harm-reduction purposes only. Trestolone (MENT) is a Schedule III controlled substance in the United States. It has not been approved by the FDA for any indication. Although Population Council clinical trials exist for its contraceptive application, it remains an experimental compound with limited long-term safety data. This content does not constitute medical advice. Always consult a licensed physician before using any anabolic agent.