Trestolone

Trestolone, or MENT, has direct human androgen, replacement and sperm-suppression data, plus a large historical breast-cancer trial. That establishes potent human activity. Cited controlled studies did not measure healthy-human muscle gain or athletic performance, and the male implant trials exposed important problems with release, sexual function and blood pressure.

synthetic 19-nor androgen-receptor agonist

MENT means 7-alpha-methyl-19-nortestosterone
Trestolone acetate is the ester used in most implant studies
Human evidence includes small male trials and 335 MENT recipients in a historical randomized oncology trial.
WADA explicitly prohibits trestolone and MENT in 2026

Are trestolone, MENT, and trestolone acetate the same thing?

MENT and trestolone name the parent androgen 7-alpha-methyl-19-nortestosterone. Trestolone acetate, also called MENT acetate, is an ester that was placed in subdermal implants and hydrolyzed to the parent drug; its mass and release data cannot be treated as an equal mass of free trestolone.

The compound is a small-molecule steroid. The name MENT alone does not tell you whether a product contains the parent steroid, the acetate ester, the implant formulation used in trials, or the stated compound at all.

PubChem · parent identity

Official chemical identity record

National Center for Biotechnology Information. PubChem CID 9838899.

The record identifies trestolone as 7-alpha-methyl-19-nortestosterone, formula C19H28O2, molecular weight 288.4 g/mol, and CAS 3764-87-2.

Study design: Chemical database record

A chemical identity record is not approval or product-authentication evidence.

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Suvisaari et al. · implant release PK

Human pharmacokinetic study

Suvisaari J, Moo-Young A, Juhakoski A, Elomaa K, Saleh SI, Lähteenmäki P. Contraception. 1999. DOI 10.1016/S0010-7824(99)00095-5.

Fifteen healthy men were randomized to one, two, or four MENT-acetate implants for four weeks. The ester was rapidly hydrolyzed, and parent concentrations and estimated daily release rose with implant number.

Participants / model: 15 healthy Finnish men
Treatment: One, two, or four 112 mg MENT-acetate implants
Follow-up: 4 weeks
Study design: Randomized parallel implant PK study

Implant release data cannot determine the terminal half-life of free trestolone or another formulation.

Read the original source

What makes MENT pharmacologically different from testosterone?

MENT is a potent androgen-receptor agonist that is not amplified by 5-alpha reduction in androgen-sensitive reproductive tissues. It can still be aromatized, and cell studies also show progesterone-receptor activity, so the shorthand 'non-DHT androgen' does not mean estrogenic or progestogenic biology disappears.

Structure-activity work attributed much of MENT's high potency to androgen-receptor affinity. Receptor-transactivation studies found activity through androgen and progesterone receptors and showed that an aromatized metabolite can activate estrogen receptors. These experiments measured receptor activity; they did not measure clinical benefits or adverse-event rates.

Kumar et al. · receptor potency

Preclinical mechanism study

Kumar N, Crozat A, Li F, Catterall JF, Bardin CW, Sundaram K. Journal of Steroid Biochemistry and Molecular Biology. 1999;71(5-6):213-222. DOI 10.1016/S0960-0760(99)00143-0.

Receptor assays reported an androgen-receptor competition IC50 of 1.82 nM for MENT and 6.95 nM for testosterone; reporter and castrated-rat comparisons supported higher potency in those systems.

Participants / model: Receptor systems and preclinical models
Treatment: MENT and comparator androgens
Study design: Structure-activity and receptor study

Potency in these systems is not a human performance outcome.

Read the original source

García-Becerra et al. · AR, PR, and aromatized metabolite

Cell receptor-transactivation study

García-Becerra R, Ordaz-Rosado D, Noé G, Chávez B, Cooney AJ, Larrea F. Reproduction. 2012;143(2):211-219. DOI 10.1530/REP-11-0171.

MENT activated androgen and progesterone receptor systems; its aromatized derivative activated estrogen receptors in cell assays.

Participants / model: Transfected cell systems
Treatment: MENT, progestins, and receptor comparators
Study design: In-vitro receptor-transactivation study

Cell activity does not quantify clinical estrogenic or progestogenic effects.

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Sundaram et al. · 5-alpha boundary

Preclinical androgen-biology study

Kumar N, Didolkar AK, Monder C, Bardin CW, Sundaram K. Endocrinology. 1992;130(6):3677-3683. DOI 10.1210/endo.130.6.1597164.

Animal experiments supported the claim that MENT activity is not amplified in reproductive tissues by 5-alpha reduction as testosterone activity is.

Participants / model: Male rat reproductive-tissue models
Treatment: MENT and testosterone comparators
Study design: Controlled preclinical study

The rat study collected no human prostate-safety or therapeutic outcome.

Read the original source

What has MENT done in human trials?

Small randomized male studies show androgen replacement, sexual-function effects and strong hormone or sperm suppression. A larger historical cancer trial confirms human activity in a very different population.

In 45 healthy men, the highest implant group had mean testosterone, LH and FSH reductions of about 93%, 97% and 95%, with recovery after removal. A 35-man implant study found azoospermia in eight of 11 evaluable recipients at the highest implant count. Neither study measured pregnancy prevention.

A 20-man hypogonadal crossover found better waking erections with both MENT and testosterone, without MENT superiority. Broader sexual and mood results differed by center. A separate 16-man replacement study found that two implants maintained more androgen-dependent measures than one, but lumbar-spine bone density fell about 2.8 to 3.0% in both groups.

The 1973 randomized double-blind oncology trial included 500 eligible women, 335 assigned MENT acetate. Objective tumor regressions occurred in 15.3%, 22.3% and 28.2% across its three MENT dose groups; overall survival did not differ. These are tumor outcomes in metastatic breast cancer, not a muscle-gain estimate.

Noé et al. · 45-man implant study

Human implant pharmacology study

Noé G, Suvisaari J, Martin C, Moo-Young AJ, Sundaram K, Saleh SI, Quintero E, Croxatto HB, Lähteenmäki P. Human Reproduction. 1999;14(9):2200-2206. DOI 10.1093/humrep/14.9.2200.

Forty-five healthy men received one, two, or four MENT-acetate implants for 28 days. Two and four implants produced near-maximal suppression; the four-implant group had mean reductions of about 93% in testosterone, 80% in DHT, 97% in LH, and 95% in FSH, with recovery after removal.

Participants / model: 45 healthy men
Treatment: One, two, or four subdermal MENT-acetate implants
Follow-up: 28 days plus post-removal follow-up
Study design: Parallel implant pharmacology study
Funding: Population Council-associated development program

Small and short, without a placebo or clinical contraceptive endpoint.

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von Eckardstein et al. · six-to-twelve-month implants

Human male-contraception trial

von Eckardstein S, Noe G, Brache V, Nieschlag E, Croxatto H, Alvarez F, Moo-Young A, Sivin I, Kumar N, Small M, Sundaram K, International Committee for Contraception Research. Journal of Clinical Endocrinology and Metabolism. 2003. DOI 10.1210/jc.2002-022043.

Thirty-five healthy men received one, two, or four implants. Eight of 11 evaluable men in the four-implant group became azoospermic; red-cell indices rose, SHBG fell, and moderate transient lipid and liver-enzyme changes were reported.

Participants / model: 35 healthy men
Treatment: One, two, or four MENT-acetate implants
Follow-up: 6 months; extensions to 9 or 12 months in higher groups
Study design: Non-placebo dose-group clinical trial
Funding: Population Council-associated program

No pregnancy endpoint, no placebo, few participants, and incomplete sperm suppression in the highest group.

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Anderson et al. · crossover against testosterone

Randomized crossover human trial

Anderson RA, Martin CW, Kung AW, Everington D, Pun TC, Tan KC, Bancroft J, Sundaram K, Moo-Young AJ, Baird DT. Journal of Clinical Endocrinology and Metabolism. 1999;84(10):3556-3562. DOI 10.1210/jcem.84.10.6028.

Twenty hypogonadal men received six-week MENT and testosterone periods in a randomized crossover. Both improved waking erections. Broader sexual and mood measures differed by center, without demonstrated MENT superiority.

Participants / model: 20 hypogonadal men
Treatment: MENT-acetate implants versus intramuscular testosterone enanthate
Follow-up: 6 weeks per treatment after washout
Study design: Randomized crossover trial

Tiny, short, and dependent in part on subjective outcomes; not a performance study.

Read the original source

Anderson et al. · 24-week hypogonadal study

Randomized human replacement study

Anderson RA, Wallace AM, Sattar N, Kumar N, Sundaram K. Journal of Clinical Endocrinology and Metabolism. 2003;88(6):2784-2793. DOI 10.1210/jc.2002-021960.

Sixteen hypogonadal men were randomized to one or two MENT-acetate implants for 24 weeks. Two implants maintained most measured androgen-dependent functions, while one was inadequate; prostate measures fell, but bone mineral density fell in both groups.

Participants / model: 16 hypogonadal men
Treatment: One or two MENT-acetate implants
Follow-up: 24 weeks
Study design: Randomized two-group replacement study

The study had 16 participants and no placebo or testosterone comparator, leaving long-term benefit and safety unresolved.

Read the original source

Talley et al. · 335 MENT recipients in a randomized oncology trial

Randomized double-blind human oncology study

Talley RW, Haines CR, Waters MN, Goldenberg IS, Olson KB, Bisel HF. A dose-response evaluation of androgens in the treatment of metastatic breast cancer. 1973. DOI 10.1002/1097-0142(197308)32:2<315::aid-cncr2820320206>3.0.co;2-q.

The trial enrolled 527 women with metastatic breast cancer; 500 were eligible across five androgen arms, including 335 assigned trestolone acetate. Objective regressions were 17/111 (15.3%), 27/121 (22.3%) and 29/103 (28.2%) across increasing MENT dose labels. The log-dose trend was borderline (chi-square 4.61, p about .05), and total survival did not differ. Virilism dominated reported abnormalities; drug- and disease-related events were pooled.

The abstract and methods disagree on administration frequency. NCI cooperative-group support. The study measured tumor response in severely ill women, with no muscle or athletic endpoint.

Read the original source

Is MENT ten or twenty-three times more anabolic than testosterone?

Those multipliers come from animal myotropic assays and historical descriptions. No controlled human muscle or strength comparison validates them.

Rat levator-ani growth, receptor affinity and tumor regression demonstrate different kinds of androgen activity. They do not yield a human dose-equivalent bodybuilding multiplier.

The contraceptive comparison recorded no significant MENT-arm weight change over 24 weeks and did not measure body composition or strength. The 56-rat muscle, fat and bone study tested restoration after androgen deprivation. Cited controlled healthy-human studies did not report hypertrophy, sprint, or endurance outcomes.

Kumar et al. · receptor potency

Preclinical mechanism study

Kumar N, Crozat A, Li F, Catterall JF, Bardin CW, Sundaram K. Journal of Steroid Biochemistry and Molecular Biology. 1999;71(5-6):213-222. DOI 10.1016/S0960-0760(99)00143-0.

Receptor assays reported an androgen-receptor competition IC50 of 1.82 nM for MENT and 6.95 nM for testosterone; reporter and castrated-rat comparisons supported higher potency in those systems.

Participants / model: Receptor systems and preclinical models
Treatment: MENT and comparator androgens
Study design: Structure-activity and receptor study

Potency in these systems is not a human performance outcome.

Read the original source

Talley et al. · 335 MENT recipients in a randomized oncology trial

Randomized double-blind human oncology study

Talley RW, Haines CR, Waters MN, Goldenberg IS, Olson KB, Bisel HF. A dose-response evaluation of androgens in the treatment of metastatic breast cancer. 1973. DOI 10.1002/1097-0142(197308)32:2<315::aid-cncr2820320206>3.0.co;2-q.

The trial enrolled 527 women with metastatic breast cancer; 500 were eligible across five androgen arms, including 335 assigned trestolone acetate. Objective regressions were 17/111 (15.3%), 27/121 (22.3%) and 29/103 (28.2%) across increasing MENT dose labels. The log-dose trend was borderline (chi-square 4.61, p about .05), and total survival did not differ. Virilism dominated reported abnormalities; drug- and disease-related events were pooled.

The abstract and methods disagree on administration frequency. NCI cooperative-group support. The study measured tumor response in severely ill women, with no muscle or athletic endpoint.

Read the original source

Walton et al. · MENT arm shortened to 24 weeks

Randomized human contraception trial

Walton MJ, Kumar N, Baird DT, Ludlow H, Anderson RA. Journal of Andrology. 2007;28(5):679-688. DOI 10.2164/jandrol.107.002683.

Twenty-nine healthy men were randomized open-label: 13 MENT plus etonogestrel and 16 testosterone plus etonogestrel. At week 12, 8/10 evaluable MENT and 13/16 testosterone recipients had fewer than one million sperm/mL. Suppression escaped as MENT release fell. Six of 13 assigned MENT recipients had libido/erectile complaints, with two early withdrawals for those complaints. MENT exposure was shortened to 24 weeks. Systolic pressure rose, hemoglobin rose transiently and HDL fell; mean MENT weight did not change significantly. Nine of ten MENT completers recovered above 20 million sperm/mL within 16 weeks after removal.

Participants / model: 29 healthy men
Treatment: MENT-acetate implants plus etonogestrel versus testosterone pellets plus etonogestrel
Follow-up: 48 weeks planned; MENT shortened to 24 weeks, then recovery
Study design: Randomized active-comparator trial
Funding: UK Medical Research Council and Department for International Development

The shared progestin and falling implant release complicate causal attribution and steady-exposure interpretation.

Read the original source

Sinnesael et al. · aged orchidectomized rats

Controlled animal muscle and bone study

Sinnesael M, Boonen S, Claessens F, Gielen E, Vanderschueren D. International Journal of Andrology. 2011;34(6 Pt 2):e601-e611. DOI 10.1111/j.1365-2605.2011.01198.x.

Fifty-six male Wistar rats were divided among seven groups of eight. After orchidectomy, four months of pump-delivered MENT restored several muscle and trabecular-bone measures and reduced fat mass; testosterone produced stronger periosteal bone formation in some comparisons.

Participants / model: Adult and aged male Wistar rats; seven groups of eight
Treatment: Orchidectomy or sham surgery followed by vehicle, MENT, or testosterone via osmotic pumps
Follow-up: Two months after surgery before four months of treatment
Study design: Controlled hormone-deficiency animal study
Funding: Academic and industry-linked support disclosed in the paper

The model used androgen-deficient rats. It does not establish hypertrophy or bone benefit in healthy people; the 16-man MENT replacement study reported lumbar-spine bone-density loss.

Read the original source

Registry search · no performance outcome

Registry search

PubMed and ClinicalTrials.gov search results.

The indexed human records concern pharmacokinetics, androgen replacement, sexual function, and male contraception. None reports a controlled trial of hypertrophy, strength, sprinting, endurance, or sports performance.

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Which problems appeared in the trials?

The male studies recorded deep reproductive suppression, individual libido or erectile problems, systolic-pressure increases, HDL reductions and blood-count changes. One replacement study also found lumbar-spine bone loss.

In the MENT/etonogestrel comparison, hemoglobin rose transiently, HDL fell, estradiol fell markedly and testicular volume fell temporarily. Mean weight and bone density did not significantly change in that study. The shared progestin and falling release complicate attribution.

The 16-man replacement study’s lumbar-spine BMD fell about 2.8 to 3.0%. Short PSA or prostate-volume reductions do not establish long-term prostate safety. Isolated liver or muscle-enzyme abnormalities and the lack of large follow-up leave uncommon harms unresolved.

The historical oncology report pooled drug- and disease-related events. Its virilism and other abnormalities cannot supply a clean modern adverse-event rate for healthy men.

Walton et al. · MENT arm shortened to 24 weeks

Randomized human contraception trial

Walton MJ, Kumar N, Baird DT, Ludlow H, Anderson RA. Journal of Andrology. 2007;28(5):679-688. DOI 10.2164/jandrol.107.002683.

Twenty-nine healthy men were randomized open-label: 13 MENT plus etonogestrel and 16 testosterone plus etonogestrel. At week 12, 8/10 evaluable MENT and 13/16 testosterone recipients had fewer than one million sperm/mL. Suppression escaped as MENT release fell. Six of 13 assigned MENT recipients had libido/erectile complaints, with two early withdrawals for those complaints. MENT exposure was shortened to 24 weeks. Systolic pressure rose, hemoglobin rose transiently and HDL fell; mean MENT weight did not change significantly. Nine of ten MENT completers recovered above 20 million sperm/mL within 16 weeks after removal.

Participants / model: 29 healthy men
Treatment: MENT-acetate implants plus etonogestrel versus testosterone pellets plus etonogestrel
Follow-up: 48 weeks planned; MENT shortened to 24 weeks, then recovery
Study design: Randomized active-comparator trial
Funding: UK Medical Research Council and Department for International Development

The shared progestin and falling implant release complicate causal attribution and steady-exposure interpretation.

Read the original source

Anderson et al. · 24-week hypogonadal study

Randomized human replacement study

Anderson RA, Wallace AM, Sattar N, Kumar N, Sundaram K. Journal of Clinical Endocrinology and Metabolism. 2003;88(6):2784-2793. DOI 10.1210/jc.2002-021960.

Sixteen hypogonadal men were randomized to one or two MENT-acetate implants for 24 weeks. Two implants maintained most measured androgen-dependent functions, while one was inadequate; prostate measures fell, but bone mineral density fell in both groups.

Participants / model: 16 hypogonadal men
Treatment: One or two MENT-acetate implants
Follow-up: 24 weeks
Study design: Randomized two-group replacement study

The study had 16 participants and no placebo or testosterone comparator, leaving long-term benefit and safety unresolved.

Read the original source

Suvisaari et al. · intramuscular PK/PD

Human pharmacokinetic and pharmacodynamic study

Suvisaari J, Sundaram K, Noé G, Kumar N, Aguillaume C, Tsong YY, Lähteenmäki P, Bardin CW. Human Reproduction. 1997;12(5):967-973. DOI 10.1093/humrep/12.5.967.

In one experiment, 18 healthy men received a single intramuscular MENT suspension; concentrations peaked at about one to two hours, clearance averaged 1,790 L/day, and the apparent terminal half-life was 224 minutes versus 40 minutes after previously reported intravenous administration. A separate 24-man experiment used six daily injections and measured hormonal suppression.

Participants / model: 18 healthy men in single-dose PK; 24 in repeated-dose PD
Treatment: Experimental intramuscular MENT suspension
Follow-up: Nine-day sampling after a single dose; six daily injections in the PD experiment
Study design: Dose-ranging PK and short PD studies

The authors interpreted the longer intramuscular terminal phase as depot absorption or flip-flop kinetics. Results also describe isolated AST and LD elevations despite the abstract reporting no side effects. This suspension does not define implant, gel, or retail-product PK.

Read the original source

Talley et al. · 335 MENT recipients in a randomized oncology trial

Randomized double-blind human oncology study

Talley RW, Haines CR, Waters MN, Goldenberg IS, Olson KB, Bisel HF. A dose-response evaluation of androgens in the treatment of metastatic breast cancer. 1973. DOI 10.1002/1097-0142(197308)32:2<315::aid-cncr2820320206>3.0.co;2-q.

The trial enrolled 527 women with metastatic breast cancer; 500 were eligible across five androgen arms, including 335 assigned trestolone acetate. Objective regressions were 17/111 (15.3%), 27/121 (22.3%) and 29/103 (28.2%) across increasing MENT dose labels. The log-dose trend was borderline (chi-square 4.61, p about .05), and total survival did not differ. Virilism dominated reported abnormalities; drug- and disease-related events were pooled.

The abstract and methods disagree on administration frequency. NCI cooperative-group support. The study measured tumor response in severely ill women, with no muscle or athletic endpoint.

Read the original source

Is there a useful human half-life for planning exposure?

Human PK is formulation-specific. In the single-injection study, intramuscular suspension peaked at about one to two hours and had an apparent terminal half-life of 224 minutes, compared with 40 minutes after previously reported intravenous administration. The authors attributed the longer intramuscular phase to depot absorption. Implants and gel require separate data.

Why the pharmacokinetic results do not collapse to one number
Formulation	Human evidence	What remains unknown
Subdermal MENT-acetate implants	15 healthy men randomized to one, two, or four implants for four weeks; release and steady concentrations scaled with implant number	Terminal elimination of parent drug after a defined soluble dose
Intramuscular suspension	18 healthy men after one injection; peak about one to two hours; clearance 1,790 L/day; apparent terminal half-life 224 minutes	Comparability to intravenous drug, acetate implants, gel, or unverified products

Suvisaari et al. · implant release PK

Human pharmacokinetic study

Suvisaari J, Moo-Young A, Juhakoski A, Elomaa K, Saleh SI, Lähteenmäki P. Contraception. 1999. DOI 10.1016/S0010-7824(99)00095-5.

Fifteen healthy men were randomized to one, two, or four MENT-acetate implants for four weeks. The ester was rapidly hydrolyzed, and parent concentrations and estimated daily release rose with implant number.

Participants / model: 15 healthy Finnish men
Treatment: One, two, or four 112 mg MENT-acetate implants
Follow-up: 4 weeks
Study design: Randomized parallel implant PK study

Implant release data cannot determine the terminal half-life of free trestolone or another formulation.

Read the original source

Suvisaari et al. · intramuscular PK/PD

Human pharmacokinetic and pharmacodynamic study

Suvisaari J, Sundaram K, Noé G, Kumar N, Aguillaume C, Tsong YY, Lähteenmäki P, Bardin CW. Human Reproduction. 1997;12(5):967-973. DOI 10.1093/humrep/12.5.967.

In one experiment, 18 healthy men received a single intramuscular MENT suspension; concentrations peaked at about one to two hours, clearance averaged 1,790 L/day, and the apparent terminal half-life was 224 minutes versus 40 minutes after previously reported intravenous administration. A separate 24-man experiment used six daily injections and measured hormonal suppression.

Participants / model: 18 healthy men in single-dose PK; 24 in repeated-dose PD
Treatment: Experimental intramuscular MENT suspension
Follow-up: Nine-day sampling after a single dose; six daily injections in the PD experiment
Study design: Dose-ranging PK and short PD studies

The authors interpreted the longer intramuscular terminal phase as depot absorption or flip-flop kinetics. Results also describe isolated AST and LD elevations despite the abstract reporting no side effects. This suspension does not define implant, gel, or retail-product PK.

Read the original source

Is trestolone approved or allowed in tested sport?

No FDA-approved trestolone product appears in the cited US records. One US MENT gel study is registered as completed without posted results, which does not create an approval. WADA's 2026 list explicitly names trestolone and MENT as anabolic agents prohibited at all times.

NCT00812630 · no posted results

Clinical trial registry record

ClinicalTrials.gov. NCT00812630.

The phase 1 MENT-gel study is marked completed with 68 actual participants and no posted results. The record describes a six-man four-week open pilot and a 62-man randomized, double-blind, placebo-controlled 12-week study centered on blood pressure, reproductive hormones, sperm, and safety.

Participants / model: 68 actual participants: six in an open pilot and 62 in the randomized main study
Treatment: Transdermal MENT gel
Follow-up: Four-week pilot and 12-week main study
Study design: Phase 1 open pilot followed by randomized, double-blind, placebo-controlled study

The record was last verified in August 2017 and posts no results. Completion alone supplies no outcome.

Read the original source

WADA 2026 · trestolone and MENT named

Official anti-doping standard

World Anti-Doping Agency. The 2026 Prohibited List, effective 1 January 2026.

Section S1.1 explicitly names trestolone and 7-alpha-methyl-19-nortestosterone, MENT, among anabolic androgenic steroids prohibited at all times.

Participants / model: Athletes subject to the World Anti-Doping Code
Follow-up: Calendar year 2026
Study design: Anti-doping prohibited list
Funding: World Anti-Doping Agency

Sport prohibition is separate from medical approval.

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What compound-specific evidence comes from Chinese and Russian sources?

A Wenzhou Medical University and Population Council team studied MENT in GnRH-suppressed male rats and found age-dependent changes in testicular 11-beta-hydroxysteroid-dehydrogenase gene expression. Public Chinese and Russian sources added no separate human performance, contraceptive, pharmacokinetic, or safety program.

Zhou et al. · Chinese-origin rat testis study

Controlled preclinical endocrine-mechanism study

Zhou HY, Chen XX, Lin H, Fei AL, Ge RS. Asian Journal of Andrology. 2014;16(6):811-816. DOI 10.4103/1008-682X.132471.

In GnRH-antagonist-treated male rats at postnatal days 21 and 90, luteinizing hormone, testosterone, and MENT were used to probe testicular 11-beta-HSD regulation. MENT increased 11-beta-HSD1 and 11-beta-HSD2 mRNA in the younger animals under the reported conditions, with age-dependent patterns.

Participants / model: Male rats studied at postnatal days 21 and 90
Treatment: GnRH blockade followed by hormone or androgen interventions including MENT
Follow-up: Short mechanistic treatment around age-specific endpoints
Study design: Controlled rat testis gene-expression and localization study
Funding: Chinese academic funding and Population Council collaboration

Rat data do not establish human clinical outcomes.

Read the original source

Regional literature search · no new human outcome

Regional literature search

Chinese and Russian literature and trial-registry search results.

The cited Chinese records include a China-affiliated rat-testis mechanism paper and an index-only 1993 review or commentary item. The cited Russian records add no compound-specific human or animal outcome paper. Neither group adds human performance or pharmacokinetic evidence.

The 1993 Chinese item appears to be a review rather than a primary result. Public Russian results were secondary or unrelated uses, not controlled performance or longevity trials.

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Why did the MENT contraceptive comparison fall short?

Sperm suppression escaped as the implants released less drug. Sexual-function complaints also led the safety committee to shorten MENT treatment from 48 planned weeks to 24.

The open randomized comparison assigned 13 men to MENT plus etonogestrel and 16 to testosterone plus etonogestrel. At week 12, eight of ten evaluable MENT recipients and 13 of 16 testosterone recipients were below one million sperm/mL.

Six of the 13 assigned MENT recipients reported reduced libido or erectile function; two withdrew for those complaints. Nine of ten MENT completers recovered above 20 million sperm/mL within 16 weeks after removal. These small followed groups do not establish reliable contraception or predict every person’s fertility recovery.

Walton et al. · MENT arm shortened to 24 weeks

Randomized human contraception trial

Walton MJ, Kumar N, Baird DT, Ludlow H, Anderson RA. Journal of Andrology. 2007;28(5):679-688. DOI 10.2164/jandrol.107.002683.

Twenty-nine healthy men were randomized open-label: 13 MENT plus etonogestrel and 16 testosterone plus etonogestrel. At week 12, 8/10 evaluable MENT and 13/16 testosterone recipients had fewer than one million sperm/mL. Suppression escaped as MENT release fell. Six of 13 assigned MENT recipients had libido/erectile complaints, with two early withdrawals for those complaints. MENT exposure was shortened to 24 weeks. Systolic pressure rose, hemoglobin rose transiently and HDL fell; mean MENT weight did not change significantly. Nine of ten MENT completers recovered above 20 million sperm/mL within 16 weeks after removal.

Participants / model: 29 healthy men
Treatment: MENT-acetate implants plus etonogestrel versus testosterone pellets plus etonogestrel
Follow-up: 48 weeks planned; MENT shortened to 24 weeks, then recovery
Study design: Randomized active-comparator trial
Funding: UK Medical Research Council and Department for International Development

The shared progestin and falling implant release complicate causal attribution and steady-exposure interpretation.

Read the original source

What do the newer papers add?

Detection and product-identity information. They do not add a new muscle-building trial.

The 2026 four-volunteer paper mapped urinary metabolites. A detection window is not a plasma half-life, effect duration or safety study.

The 2025 Australian product-testing study found one vial labeled parent MENT that instead matched trestolone acetate. Its concentration could not be quantified. That sample illustrates a formulation mismatch without establishing how often it occurs.

The completed transdermal-gel registry lists 68 participants and still has no posted results.

Piper et al. · four-man urinary-metabolism study

Human excretion and anti-doping analytical study

Piper T, Fusshöller G, Thevis M. Drug Testing and Analysis. 2026;18(3):341-353. Epub 17 December 2025. DOI 10.1002/dta.70018.

One 49-year-old man received deuterated trestolone acetate and three male sport students received nondeuterated material by mouth. Fifty labelled urinary metabolites were detected; 28 appeared in all four volunteers and 14 were screened further. Parent trestolone was detected for 23 to 43 hours and the longest candidate markers for 68 to 92 hours after a single administration.

Participants / model: Four male volunteers; one deuterated-material experiment and three nondeuterated-material experiments
Treatment: Single oral research administration of trestolone acetate
Follow-up: Urine collection through six or seven days
Study design: Open human excretion and analytical-method study
Funding: World Anti-Doping Agency, Manfred Donike Institute, and German federal funding; authors reported no conflicts

The study was designed to identify urinary markers. It collected no efficacy endpoint, structured adverse-event series, systemic concentration-time profile, or plasma half-life.

Read the original source

Piatkowski et al. · one parent-versus-acetate mismatch

Analytical product identity study

Piatkowski T, Coomber R, Francis C, Kill E, Davey G, Cresswell S, White A, Harding M, Blakey K, Reeve S, Walters B, Puljević C, Ferris J, Barratt MJ. Anabolic-androgenic steroid testing as a tool for consumer engagement and harm reduction: a sequential explanatory mixed-method study. 2025. DOI 10.1186/s12954-025-01270-4.

Among 58 submitted AAS products, 46 were analytically assessable. One sample labeled parent MENT matched trestolone acetate; concentration could not be established without reference material. One volunteered sample cannot establish a market-wide mismatch rate.

This is chemical product testing, without a trestolone efficacy or clinical safety cohort.

Read the original source

NCT00812630 · no posted results

Clinical trial registry record

ClinicalTrials.gov. NCT00812630.

The phase 1 MENT-gel study is marked completed with 68 actual participants and no posted results. The record describes a six-man four-week open pilot and a 62-man randomized, double-blind, placebo-controlled 12-week study centered on blood pressure, reproductive hormones, sperm, and safety.

Participants / model: 68 actual participants: six in an open pilot and 62 in the randomized main study
Treatment: Transdermal MENT gel
Follow-up: Four-week pilot and 12-week main study
Study design: Phase 1 open pilot followed by randomized, double-blind, placebo-controlled study

The record was last verified in August 2017 and posts no results. Completion alone supplies no outcome.

Read the original source

Studies and sources

PubChem · parent identity

Official chemical identity record

National Center for Biotechnology Information. PubChem CID 9838899.

The record identifies trestolone as 7-alpha-methyl-19-nortestosterone, formula C19H28O2, molecular weight 288.4 g/mol, and CAS 3764-87-2.

Study design: Chemical database record

A chemical identity record is not approval or product-authentication evidence.

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Kumar et al. · receptor potency

Preclinical mechanism study

Kumar N, Crozat A, Li F, Catterall JF, Bardin CW, Sundaram K. Journal of Steroid Biochemistry and Molecular Biology. 1999;71(5-6):213-222. DOI 10.1016/S0960-0760(99)00143-0.

Receptor assays reported an androgen-receptor competition IC50 of 1.82 nM for MENT and 6.95 nM for testosterone; reporter and castrated-rat comparisons supported higher potency in those systems.

Participants / model: Receptor systems and preclinical models
Treatment: MENT and comparator androgens
Study design: Structure-activity and receptor study

Potency in these systems is not a human performance outcome.

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García-Becerra et al. · AR, PR, and aromatized metabolite

Cell receptor-transactivation study

García-Becerra R, Ordaz-Rosado D, Noé G, Chávez B, Cooney AJ, Larrea F. Reproduction. 2012;143(2):211-219. DOI 10.1530/REP-11-0171.

MENT activated androgen and progesterone receptor systems; its aromatized derivative activated estrogen receptors in cell assays.

Participants / model: Transfected cell systems
Treatment: MENT, progestins, and receptor comparators
Study design: In-vitro receptor-transactivation study

Cell activity does not quantify clinical estrogenic or progestogenic effects.

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Sundaram et al. · 5-alpha boundary

Preclinical androgen-biology study

Kumar N, Didolkar AK, Monder C, Bardin CW, Sundaram K. Endocrinology. 1992;130(6):3677-3683. DOI 10.1210/endo.130.6.1597164.

Animal experiments supported the claim that MENT activity is not amplified in reproductive tissues by 5-alpha reduction as testosterone activity is.

Participants / model: Male rat reproductive-tissue models
Treatment: MENT and testosterone comparators
Study design: Controlled preclinical study

The rat study collected no human prostate-safety or therapeutic outcome.

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Noé et al. · 45-man implant study

Human implant pharmacology study

Noé G, Suvisaari J, Martin C, Moo-Young AJ, Sundaram K, Saleh SI, Quintero E, Croxatto HB, Lähteenmäki P. Human Reproduction. 1999;14(9):2200-2206. DOI 10.1093/humrep/14.9.2200.

Forty-five healthy men received one, two, or four MENT-acetate implants for 28 days. Two and four implants produced near-maximal suppression; the four-implant group had mean reductions of about 93% in testosterone, 80% in DHT, 97% in LH, and 95% in FSH, with recovery after removal.

Participants / model: 45 healthy men
Treatment: One, two, or four subdermal MENT-acetate implants
Follow-up: 28 days plus post-removal follow-up
Study design: Parallel implant pharmacology study
Funding: Population Council-associated development program

Small and short, without a placebo or clinical contraceptive endpoint.

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Suvisaari et al. · implant release PK

Human pharmacokinetic study

Suvisaari J, Moo-Young A, Juhakoski A, Elomaa K, Saleh SI, Lähteenmäki P. Contraception. 1999. DOI 10.1016/S0010-7824(99)00095-5.

Fifteen healthy men were randomized to one, two, or four MENT-acetate implants for four weeks. The ester was rapidly hydrolyzed, and parent concentrations and estimated daily release rose with implant number.

Participants / model: 15 healthy Finnish men
Treatment: One, two, or four 112 mg MENT-acetate implants
Follow-up: 4 weeks
Study design: Randomized parallel implant PK study

Implant release data cannot determine the terminal half-life of free trestolone or another formulation.

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Anderson et al. · 24-week hypogonadal study

Randomized human replacement study

Anderson RA, Wallace AM, Sattar N, Kumar N, Sundaram K. Journal of Clinical Endocrinology and Metabolism. 2003;88(6):2784-2793. DOI 10.1210/jc.2002-021960.

Sixteen hypogonadal men were randomized to one or two MENT-acetate implants for 24 weeks. Two implants maintained most measured androgen-dependent functions, while one was inadequate; prostate measures fell, but bone mineral density fell in both groups.

Participants / model: 16 hypogonadal men
Treatment: One or two MENT-acetate implants
Follow-up: 24 weeks
Study design: Randomized two-group replacement study

The study had 16 participants and no placebo or testosterone comparator, leaving long-term benefit and safety unresolved.

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Anderson et al. · crossover against testosterone

Randomized crossover human trial

Anderson RA, Martin CW, Kung AW, Everington D, Pun TC, Tan KC, Bancroft J, Sundaram K, Moo-Young AJ, Baird DT. Journal of Clinical Endocrinology and Metabolism. 1999;84(10):3556-3562. DOI 10.1210/jcem.84.10.6028.

Twenty hypogonadal men received six-week MENT and testosterone periods in a randomized crossover. Both improved waking erections. Broader sexual and mood measures differed by center, without demonstrated MENT superiority.

Participants / model: 20 hypogonadal men
Treatment: MENT-acetate implants versus intramuscular testosterone enanthate
Follow-up: 6 weeks per treatment after washout
Study design: Randomized crossover trial

Tiny, short, and dependent in part on subjective outcomes; not a performance study.

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Suvisaari et al. · intramuscular PK/PD

Human pharmacokinetic and pharmacodynamic study

Suvisaari J, Sundaram K, Noé G, Kumar N, Aguillaume C, Tsong YY, Lähteenmäki P, Bardin CW. Human Reproduction. 1997;12(5):967-973. DOI 10.1093/humrep/12.5.967.

In one experiment, 18 healthy men received a single intramuscular MENT suspension; concentrations peaked at about one to two hours, clearance averaged 1,790 L/day, and the apparent terminal half-life was 224 minutes versus 40 minutes after previously reported intravenous administration. A separate 24-man experiment used six daily injections and measured hormonal suppression.

Participants / model: 18 healthy men in single-dose PK; 24 in repeated-dose PD
Treatment: Experimental intramuscular MENT suspension
Follow-up: Nine-day sampling after a single dose; six daily injections in the PD experiment
Study design: Dose-ranging PK and short PD studies

The authors interpreted the longer intramuscular terminal phase as depot absorption or flip-flop kinetics. Results also describe isolated AST and LD elevations despite the abstract reporting no side effects. This suspension does not define implant, gel, or retail-product PK.

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von Eckardstein et al. · six-to-twelve-month implants

Human male-contraception trial

von Eckardstein S, Noe G, Brache V, Nieschlag E, Croxatto H, Alvarez F, Moo-Young A, Sivin I, Kumar N, Small M, Sundaram K, International Committee for Contraception Research. Journal of Clinical Endocrinology and Metabolism. 2003. DOI 10.1210/jc.2002-022043.

Thirty-five healthy men received one, two, or four implants. Eight of 11 evaluable men in the four-implant group became azoospermic; red-cell indices rose, SHBG fell, and moderate transient lipid and liver-enzyme changes were reported.

Participants / model: 35 healthy men
Treatment: One, two, or four MENT-acetate implants
Follow-up: 6 months; extensions to 9 or 12 months in higher groups
Study design: Non-placebo dose-group clinical trial
Funding: Population Council-associated program

No pregnancy endpoint, no placebo, few participants, and incomplete sperm suppression in the highest group.

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Walton et al. · MENT arm shortened to 24 weeks

Randomized human contraception trial

Walton MJ, Kumar N, Baird DT, Ludlow H, Anderson RA. Journal of Andrology. 2007;28(5):679-688. DOI 10.2164/jandrol.107.002683.

Twenty-nine healthy men were randomized open-label: 13 MENT plus etonogestrel and 16 testosterone plus etonogestrel. At week 12, 8/10 evaluable MENT and 13/16 testosterone recipients had fewer than one million sperm/mL. Suppression escaped as MENT release fell. Six of 13 assigned MENT recipients had libido/erectile complaints, with two early withdrawals for those complaints. MENT exposure was shortened to 24 weeks. Systolic pressure rose, hemoglobin rose transiently and HDL fell; mean MENT weight did not change significantly. Nine of ten MENT completers recovered above 20 million sperm/mL within 16 weeks after removal.

Participants / model: 29 healthy men
Treatment: MENT-acetate implants plus etonogestrel versus testosterone pellets plus etonogestrel
Follow-up: 48 weeks planned; MENT shortened to 24 weeks, then recovery
Study design: Randomized active-comparator trial
Funding: UK Medical Research Council and Department for International Development

The shared progestin and falling implant release complicate causal attribution and steady-exposure interpretation.

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NCT00812630 · no posted results

Clinical trial registry record

ClinicalTrials.gov. NCT00812630.

The phase 1 MENT-gel study is marked completed with 68 actual participants and no posted results. The record describes a six-man four-week open pilot and a 62-man randomized, double-blind, placebo-controlled 12-week study centered on blood pressure, reproductive hormones, sperm, and safety.

Participants / model: 68 actual participants: six in an open pilot and 62 in the randomized main study
Treatment: Transdermal MENT gel
Follow-up: Four-week pilot and 12-week main study
Study design: Phase 1 open pilot followed by randomized, double-blind, placebo-controlled study

The record was last verified in August 2017 and posts no results. Completion alone supplies no outcome.

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Registry search · no performance outcome

Registry search

PubMed and ClinicalTrials.gov search results.

The indexed human records concern pharmacokinetics, androgen replacement, sexual function, and male contraception. None reports a controlled trial of hypertrophy, strength, sprinting, endurance, or sports performance.

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WADA 2026 · trestolone and MENT named

Official anti-doping standard

World Anti-Doping Agency. The 2026 Prohibited List, effective 1 January 2026.

Section S1.1 explicitly names trestolone and 7-alpha-methyl-19-nortestosterone, MENT, among anabolic androgenic steroids prohibited at all times.

Participants / model: Athletes subject to the World Anti-Doping Code
Follow-up: Calendar year 2026
Study design: Anti-doping prohibited list
Funding: World Anti-Doping Agency

Sport prohibition is separate from medical approval.

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Zhou et al. · Chinese-origin rat testis study

Controlled preclinical endocrine-mechanism study

Zhou HY, Chen XX, Lin H, Fei AL, Ge RS. Asian Journal of Andrology. 2014;16(6):811-816. DOI 10.4103/1008-682X.132471.

In GnRH-antagonist-treated male rats at postnatal days 21 and 90, luteinizing hormone, testosterone, and MENT were used to probe testicular 11-beta-HSD regulation. MENT increased 11-beta-HSD1 and 11-beta-HSD2 mRNA in the younger animals under the reported conditions, with age-dependent patterns.

Participants / model: Male rats studied at postnatal days 21 and 90
Treatment: GnRH blockade followed by hormone or androgen interventions including MENT
Follow-up: Short mechanistic treatment around age-specific endpoints
Study design: Controlled rat testis gene-expression and localization study
Funding: Chinese academic funding and Population Council collaboration

Rat data do not establish human clinical outcomes.

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Regional literature search · no new human outcome

Regional literature search

Chinese and Russian literature and trial-registry search results.

The cited Chinese records include a China-affiliated rat-testis mechanism paper and an index-only 1993 review or commentary item. The cited Russian records add no compound-specific human or animal outcome paper. Neither group adds human performance or pharmacokinetic evidence.

The 1993 Chinese item appears to be a review rather than a primary result. Public Russian results were secondary or unrelated uses, not controlled performance or longevity trials.

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Piper et al. · four-man urinary-metabolism study

Human excretion and anti-doping analytical study

Piper T, Fusshöller G, Thevis M. Drug Testing and Analysis. 2026;18(3):341-353. Epub 17 December 2025. DOI 10.1002/dta.70018.

One 49-year-old man received deuterated trestolone acetate and three male sport students received nondeuterated material by mouth. Fifty labelled urinary metabolites were detected; 28 appeared in all four volunteers and 14 were screened further. Parent trestolone was detected for 23 to 43 hours and the longest candidate markers for 68 to 92 hours after a single administration.

Participants / model: Four male volunteers; one deuterated-material experiment and three nondeuterated-material experiments
Treatment: Single oral research administration of trestolone acetate
Follow-up: Urine collection through six or seven days
Study design: Open human excretion and analytical-method study
Funding: World Anti-Doping Agency, Manfred Donike Institute, and German federal funding; authors reported no conflicts

The study was designed to identify urinary markers. It collected no efficacy endpoint, structured adverse-event series, systemic concentration-time profile, or plasma half-life.

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Sinnesael et al. · aged orchidectomized rats

Controlled animal muscle and bone study

Sinnesael M, Boonen S, Claessens F, Gielen E, Vanderschueren D. International Journal of Andrology. 2011;34(6 Pt 2):e601-e611. DOI 10.1111/j.1365-2605.2011.01198.x.

Fifty-six male Wistar rats were divided among seven groups of eight. After orchidectomy, four months of pump-delivered MENT restored several muscle and trabecular-bone measures and reduced fat mass; testosterone produced stronger periosteal bone formation in some comparisons.

Participants / model: Adult and aged male Wistar rats; seven groups of eight
Treatment: Orchidectomy or sham surgery followed by vehicle, MENT, or testosterone via osmotic pumps
Follow-up: Two months after surgery before four months of treatment
Study design: Controlled hormone-deficiency animal study
Funding: Academic and industry-linked support disclosed in the paper

The model used androgen-deficient rats. It does not establish hypertrophy or bone benefit in healthy people; the 16-man MENT replacement study reported lumbar-spine bone-density loss.

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Talley et al. · 335 MENT recipients in a randomized oncology trial

Randomized double-blind human oncology study

Talley RW, Haines CR, Waters MN, Goldenberg IS, Olson KB, Bisel HF. A dose-response evaluation of androgens in the treatment of metastatic breast cancer. 1973. DOI 10.1002/1097-0142(197308)32:2<315::aid-cncr2820320206>3.0.co;2-q.

The trial enrolled 527 women with metastatic breast cancer; 500 were eligible across five androgen arms, including 335 assigned trestolone acetate. Objective regressions were 17/111 (15.3%), 27/121 (22.3%) and 29/103 (28.2%) across increasing MENT dose labels. The log-dose trend was borderline (chi-square 4.61, p about .05), and total survival did not differ. Virilism dominated reported abnormalities; drug- and disease-related events were pooled.

The abstract and methods disagree on administration frequency. NCI cooperative-group support. The study measured tumor response in severely ill women, with no muscle or athletic endpoint.

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Piatkowski et al. · one parent-versus-acetate mismatch

Analytical product identity study

Piatkowski T, Coomber R, Francis C, Kill E, Davey G, Cresswell S, White A, Harding M, Blakey K, Reeve S, Walters B, Puljević C, Ferris J, Barratt MJ. Anabolic-androgenic steroid testing as a tool for consumer engagement and harm reduction: a sequential explanatory mixed-method study. 2025. DOI 10.1186/s12954-025-01270-4.

Among 58 submitted AAS products, 46 were analytically assessable. One sample labeled parent MENT matched trestolone acetate; concentration could not be established without reference material. One volunteered sample cannot establish a market-wide mismatch rate.

This is chemical product testing, without a trestolone efficacy or clinical safety cohort.

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Why is Trestolone in B tier?

B for direct human androgen activity and experimental clinical effects. The cited studies do not include a healthy-human muscle or performance trial. Falling implant release, libido and erectile complaints, blood-pressure and lipid changes, bone findings and missing long-term safety limit what the grade means.