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Trs3.4
Trestolone (MENT) Research
Mostly mechanism / observationalLimited safety
6 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most Trestolone (MENT) 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 1995–2013 with a typical study size of 35 participants.
Based on 6 studies · 3 RCTs · 129 total participants
Confidence
Moderate
By outcome
Androgen replacement & sexual function
Mostly mechanism / observational6 studies
Male contraception & fertility
Mostly mechanism / observational4 studies
Safety profile
Mostly mechanism / observational3 studies
Muscle & anabolism
Too few graded studies1 study
Older research base
Newest study from 2013
199520042013
1RCTn=35 · small study2003
Dose-related increases in serum MENT levels and decreases in testosterone, LH, and FSH levels were observed. Effects on sperm counts were also dose related ... Eight subjects in the 4-implant group reached azoospermia ... MENT Ac ... can inhibit spermatogenesis over a prolonged period ... and has the potential to be used as a male contraceptive.
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, The Population Council. · The Journal of clinical endocrinology and metabolism (2003)
Pivotal randomized clinical trial: 35 healthy men assigned to 1, 2 or 4 subdermal MENT-acetate implants (~400 µg/day release each) as a candidate long-acting male contraceptive, by the Population Council / International Committee for Contraception Research
Dose-related suppression of testosterone, LH and FSH and dose-related suppression of sperm counts — 8 of 12 men in the 4-implant group reached azoospermia
Androgenic side effects (raised erythrocyte count/hematocrit/hemoglobin, lowered SHBG) occurred but were reversible; lipid changes were moderate and transient
Sperm concentrations fell rapidly to less than 1 x 10(6)/mL at 12 weeks in 8 of 10 subjects in the MENT group ... Thereafter, suppression was not maintained in the MENT group, and 6 men noted loss of libido ... MENT with a progestogen can achieve rapid suppression of spermatogenesis similar to testosterone, but this promising result was not sustained due to a decline in MENT release from the implants.
Walton MJ, Kumar N, Baird DT, Ludlow H, Anderson RA. · Journal of andrology (2007)
Randomized trial in 29 healthy men comparing MENT implants vs testosterone pellets, each with etonogestrel implants, for spermatogenic suppression over up to 48 weeks
MENT plus progestogen achieved rapid suppression of spermatogenesis similar to testosterone (8 of 10 men to <1 million/mL by 12 weeks) with equally suppressed gonadotropins
Crucial counter-evidence: suppression was NOT maintained because MENT release from the implants declined, and 6 men reported loss of libido — a delivery-system failure, not a potency failure; HDL-C fell and hemoglobin rose in both groups
Both MENT and TE treatment resulted in significant increases in sexual interest and activity, spontaneous erection ... and increases in positive moods ... These results demonstrate that MENT has similar effects on sexual activity and mood states as testosterone in hypogonadal men ... these results support its development as a potential androgen replacement therapy.
Anderson RA, Martin CW, Kung AW, Everington D, Pun TC, Tan KC, Bancroft J, Sundaram K, Moo-Young AJ, Baird DT. · The Journal of clinical endocrinology and metabolism (1999)
Randomized crossover trial in 20 hypogonadal men (Edinburgh and Hong Kong) comparing MENT-acetate implants with testosterone enanthate injections, each for 6 weeks, with diaries, interviews, questionnaires and nocturnal penile tumescence
MENT maintained sexual interest/activity, spontaneous and nocturnal erections, and positive mood comparably to testosterone in the Edinburgh group — physiological NPT evidence of androgenicity
Outcome anchor for MENT's androgen-replacement (hypogonadism) use — a genuine human signal that MENT can substitute for testosterone on sexual function and mood
Two and four implants induced maximal suppression that was maintained throughout treatment and was completely reversed after removal of the implants. The mean decreases were 93 +/- 1% for testosterone, 80 +/- 3% for DHT, 97 +/- 1% for luteinizing hormone and 95 +/- 1% for follicle stimulating hormone.
Noé G, Suvisaari J, Martin C, Moo-Young AJ, Sundaram K, Saleh SI, Quintero E, Croxatto HB, Lähteenmäki P. · Human reproduction (Oxford, England) (1999)
Dose-finding study in 45 healthy men receiving 1, 2 or 4 subdermal MENT-acetate implants (~500 µg/day each) for 28 days, measuring serum MENT, gonadotropins, testosterone, DHT, SHBG, PSA and IGF-1
Two to four implants produced maximal, sustained and fully reversible suppression — ~97% LH, ~95% FSH, ~93% testosterone, ~80% DHT — confirming MENT's potent gonadotropin- and androgen-suppressive effect
No serious adverse reactions and no consistent clinical-chemistry/haematology changes over the short course
7 alpha-methyl-19-nortestosterone (MENT) does not get 5 alpha-reduced due to steric hindrance from the 7 alpha-methyl group ... The fact that MENT is also aromatized to 7 alpha-methyl estradiol, a potent estrogen ... suggests that some of the anabolic actions of MENT may be mediated by this estrogen.
Sundaram K, Kumar N, Monder C, Bardin CW. · The Journal of steroid biochemistry and molecular biology (1995)
Foundational mechanism paper from the Population Council on why 19-norandrogens including MENT have high relative anabolic activity
MENT is NOT 5α-reduced (the 7α-methyl group sterically blocks it), so its androgenic potency is not amplified in the prostate — the prostate-sparing property
Crucial counterpoint: MENT IS aromatized to 7α-methylestradiol, a potent estrogen — establishing the estrogenic activity (and gynecomastia risk) that accompanies use
The ensuing search for long-acting preparations yielded testosterone buciclate and undecanoate as well as 7α-methyl-19-nortestosterone (MENT) ... the systematic development of MENT for substitution of male hypogonadism and use in male contraception by the Population Council is reviewed here.
Nieschlag E, Kumar N, Sitruk-Ware R. · Contraception (2013)
Review by the program's principals (Nieschlag, Kumar, Sitruk-Ware) of the Population Council's development of MENT for male contraception and for treatment of hypogonadism
Frames MENT among the long-acting androgens sought for male hormonal contraception, and summarizes its systematic development as a replacement and contraceptive agent
Honest context anchor: documents that MENT remained investigational — a development program, not an approved, marketed product