Trestolone

A nortestosterone derivative studied clinically for male contraception — it suppresses sperm production near-completely, which was the design goal. It has since appeared in non-medical physique use far outside the studied context.

Trestolone (MENT, 7-alpha-methyl-19-nortestosterone) is a nandrolone derivative with a methyl group at the 7 position. That blocks 5-alpha reductase, so unlike testosterone it is NOT converted into DHT — a MORE potent androgen — in scalp and prostate. It avoids that tissue-specific amplification, which is not the same as being safer for hair or prostate. It aromatises readily. It was developed as a male contraceptive because it suppresses the reproductive axis, and in non-contraceptive use that suppression is an adverse reproductive consequence rather than a feature.

Legitimate but narrow: contraception and hypogonadism studies confirm potent androgenic/anabolic activity. Physique use runs far beyond studied exposures with no data at all.

• It has genuine clinical development history, unusually for this section — studied as a hormonal male contraceptive via implants, alongside intramuscular pharmacokinetic work in healthy men and limited metabolism studies. A separate open-label study in 16 hypogonadal men found two implants maintained several androgen-dependent measures, but it did not establish superior anabolic effects and lumbar bone density DECREASED over its 24 weeks.
• MODERATE only for short-term spermatogenic suppression in small monitored trials, and the results were variable and formulation-dependent: in a 35-man implant study nobody on a single implant became oligozoospermic, while with four implants eight reached azoospermia, one oligozoospermia and two did not respond adequately. NONE SHOWN for contraceptive effectiveness, dependable azoospermia, long-term safety or predictable recovery — pregnancy prevention was never an endpoint.
• NONE SHOWN for physique or performance use in a controlled trial. Contraceptive research establishes that it suppresses the axis, not that it builds muscle safely in healthy people.
• It is a substrate for aromatase, so oestrogen-mediated effects are biologically plausible — how commonly they occur in non-medical use is unknown. Its resistance to 5-alpha reduction means the scalp and prostate profile differs from testosterone. Differs, not improves: no comparative human safety data establishes which is better.
• Class-level anabolic steroid harms apply, and no trestolone-specific frequency or comparative magnitude has been established for any of them.

Not orally active in its base form; the versions in circulation are esters for injection. It aromatises and is not a substrate for 5-alpha reductase. Its potency means small amounts produce large hormonal effects, including profound suppression — which is what the contraceptive programme was built on. No FDA-approved product exists; illicit product identity and sterility are unverifiable.

Aromatizes readily — estrogen-driven side effects are a common reported failure mode. Suppression of sperm production is the drug's designed purpose, and recovery timelines outside trial-monitored exposures are uncharted. Lipid, blood-pressure, and cardiac strain are expected class effects.

• 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 who wants children in the foreseeable future — this compound was developed specifically to suppress fertility
• FDA also identifies pulmonary embolism, deep-vein thrombosis, kidney injury, infertility and testicular shrinkage among serious risks of anabolic steroid use
• Anyone with cardiovascular disease, prostate or male breast cancer
• Children and adolescents, where androgens can close growth plates prematurely
• Women, given virilisation risk, some of which does not reverse

• Interactions have not been characterised for this compound. Other androgen labels describe altered anticoagulant activity and altered glycaemic control, so disclose exposure to any treating clinician rather than assuming.
• Any other steroid, where suppression and cardiovascular effects compound.
• Tested sport, where it is prohibited.

• It can cause profound suppression of the reproductive axis and of sperm production, but the trials included incomplete responders — magnitude varies and cannot be inferred without testing. Infertility and hypogonadism are serious risks here, not intended features.
• Tell any clinician you see that you are using it. Nothing here is a schedule or a threshold.
• Class-level severe outcomes reported with anabolic steroids apply: 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.
• Any leg swelling, chest pain, breathlessness, jaundice or dark urine is urgent assessment rather than something to track.

Endocrine and fertility recovery after anabolic-steroid use is variable, can take months, and can be incomplete — and this compound was designed around suppressing fertility, so that possibility deserves particular weight rather than less. No reliable individual prognosis exists. Anyone in a prolonged low-testosterone state after stopping needs medical assessment rather than a waiting period.

US: Schedule III anabolic steroid under the CSA; never approved for any indication.

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.

• Psychological and Non-Pharmacologic Treatments for Pain in Cancer Patients: A Systematic Review and Meta-Analysis
  J Pain Symptom Manage, 2022
• Effectiveness of conservative treatment for patellofemoral pain syndrome: A systematic review and meta-analysis
  J Rehabil Med, 2018
• Potassium dehydroandrographolide succinate injection for treat- ment of infantile pneumonia: a systematic review and Meta-analysis
  J Tradit Chin Med, 2015

• Potential interaction between exogenous anabolic steroids and sugammadex: failed reversal of rocuronium in a patient taking testosterone and trestolone acetateAnaesth Rep · 2023
• Comment on 'Potential interaction between exogenous anabolic steroids and sugammadex: failed reversal of rocuronium in a patient taking testosterone and trestolone acetate'Anaesth Rep · 2024
• Investigations Into the Human Metabolism of Trestolone (7α-Methyl-19-Nortestosterone)Drug Test Anal · 2026
• Androgen replacement therapy: present and futureDrugs · 2004
• Male contraception: expanding reproductive choiceIndian J Exp Biol · 2005
• Hormonal contraception in the maleBr Med Bull · 2000
• 7α-methyl-19-nortestosterone (MENTR): the population council's contribution to research on male contraception and treatment of hypogonadismContraception · 2013
• 7 alpha-methyl-nortestosterone (MENT): the optimal androgen for male contraceptionAnn Med · 1993
• Androgen and Luteinizing Hormone Stimulate the Function of Rat Immature Leydig Cells Through Different Transcription SignalsFront Endocrinol (Lausanne) · 2021
• 7 alpha-Methyl-19-nortestosterone: an ideal androgen for replacement therapyRecent Prog Horm Res · 1994
• Reversal of testicular function after prolonged suppression with an LHRH agonist in rhesus monkeysJ Androl · 1987
• 7Alpha-methyl-19-nortestosterone maintains sexual behavior and mood in hypogonadal menJ Clin Endocrinol Metab · 1999