✔ Evidence-Based. Scientifically Reviewed by Michael Sharpe, MSc and Dr. Michael Tamber, MD.

Trestolone (MENT) is an experimental androgen/anabolic steroid (AAS), selective Androgen receptor modulator (SARM), and progestogen drug that is being researched for potential use as a male hormonal birth control method and to treat hypogonadism. (1, 2, 3, 4)

It has never been approved for medical use, though. Trestolone is a potent 19-nortestosterone derivative from the same class of steroids as nandrolone and trenbolone, and is an agonist of the androgen receptor, the biological target of androgens such as testosterone. (5)

Being a synthetic progestogen, or progestin, it also acts as an agonist on the progesterone receptor, which is the biological target of progesterone. Trestolone has antigonadotropic effects as a result of its androgenic and progestognenic action. (1, 5)

Trestolone has contraceptive effects on men as a result of these effects, which causes reversible suppression of sperm production. (1)

Chemical Information

• Other Names: MENT, MENTR, RU-27333, 7α-Methylnandrolone, 7α-Methyl-19-nortestosterone, 7α-Methylestr-4-en-17β-ol-3-one
• CAS Number: 3764-87-2
• Chemical Structure: 7α-Methylestr-4-en-17β-ol-3-one
• Class: Anabolic Androgenic Steroid, Selective Androgen Receptor Modulator, Progestogen, Antigonadotropin
• Anabolic/Androgenic Ratio: 2300:650
• Molecular Weight: 288.431 g·mol−1

Anabolic Activity

Trestolone has a myotrophic action that is about 10 times than that of testosterone. Trestolone has an anabolic to androgenic ratio of 2300:650 (for comparison the rating is 100:100 for testosterone and 500:500 for trenbolone). (6, 10)

Not many other AAS have higher anabolic ratings, one of which known as methyltrienolone (metribolone) is rated at roughly 12000:6000 and is so potent that it serves as the gold standard for all lab assays that evaluate androgen receptor binding.

Androgen Replacement Therapy

Trestolone is the only AAS currently being produced that seems to be capable of maintaining normal male physiology, including sexual function, in the absence of any testosterone. (1, 8)

Many anecdotal reports suggest that trestolone provides a euthymic and confident feeling.

The molecule is not susceptible to metabolism by the 5-reductase enzyme but does aromatise providing estrogenic effects. (7)

It doesn’t directly impact estradiol. It aromatises into 7α-Methylestradiol (7α-Me-E2).

Researchers discovered that trestolone has anabolic efficacy that is 10 times more than testosterone while also being 12 times more suppressive to the HTPA. (10)

Although it is classed as a progestin, it's shown to have minimal affinity for the progesterone and mineralocorticoid receptors, despite trestolone being a 19-nortestosterone derivative. (9)

Dosage

400-700mcg of trestolone daily is enough to achieve the same outcomes as the average male's daily production of 4-7mg of testosterone, which is necessary to maintain muscular growth and sexual function.

One, two, and four patches that delivered 400mcg per day each were used in a clinical research on contraception to create the effective daily dosages.

• 1 patch: 400mcg (0.4mg)
• 2 patches: 800mcg (0.8mg)
• 4 patches: 1600mcg (1.6mg)

Clinical investigations with doses as low as 400-700mcg and as high as 1-2mg discovered a dosage that was quite similar to testosterone replacement dosages.

Half-Life

The estimated half-life of an intravenous injection of unesterified trestolone is only ~40 minutes for 500mcg. (13)

Due to the prolonged absorption period of intramuscular injection, a study using trestolone IM injection discovered a longer half-life of ~224 minutes. About one to two hours after the injections, peak trestolone concentrations, which were dose-dependent, were attained. (12)

Esterified versions of trestolone, such as trestolone acetate or decanoate, were tested for use due to their longer half lives.

Prostate Safe

Numerous studies support trestolone to be a prostate-safe androgen and show absence of 5α-reductase metabolism. (3, 7)

Androgen restriction treatment is primarily used to treat prostate cancer, which is androgen-dependent. In these situations, trestolone has potential to be a safer alternative to testosterone while providing similar benefits, such as reducing the risk of Alzheimers disease. (11)

Because its activity in the prostate is not magnified, a dosage of trestolone sufficient to maintain normal functioning, muscle mass and gonadotrophin production will not cause the prostate to become overstimulated.

As a result, trestolone can be given to males with the knowledge that it will have a lower risk of causing prostatic hyperplasia or prostate cancer than testosterone. (3)

Trestolone may also be considered for use in cases of prostatic hyperplasia, muscular wasting, and hypogonadism. (3)

It is the first androgen that, in comparison to testosterone, has a positive health effect, especially on the prostate, it may be used as a male contraceptive, and has potential applications with a range of disorders, including hypogonadism, prostatic hyperplasia, and muscle wasting. (3)

Male Contraceptive

Trestolone was being developed as a rapidly reversible oral or implant-based male contraceptive, it is 12 times more suppressive than testosterone. In 2013, the research came to an abrupt end without a clear reason. (10)

Its efficacy as a male contraceptive is very high, with 82% of patients azoospermic in the first six months and 100% were azoospermic in the second six months of treatment.

Testosterone is often paired with a progestin such as etonogestrel to further suppress spermatogenesis.

However, the results of a study indicate that trestolone on its own is sufficient enough to suppress spermatogenesis, and also that its efficacy as use for androgen replacement is unaffected when paired with the second compound. (5)

Recovery of Spermatogenesis

A thorough human investigation on male participants evaluated the effects of trestolone to testosterone on spermatogenesis, sex desire, and safety biomarkers related to androgen usage, both alone and in combination with the progestin etonogestrel. (13)

This was a thorough research with 29 participants who underwent 48 weeks of testing.

8 Participants received:

• Three 600mg testosterone pellets, one given every 12 weeks.
• Two trestolone pellets, each containing 135mg of trestolone acetate (predicted to release 400mcg daily).
• Both groups received 68mg etonogestrel.

After 12 weeks of supplementation, 80% of both groups' sperm production had significantly decreased, from an average of 55×106 mL to just 1×106 mL.

Recovery of spermatogenesis occurred significantly faster with trestolone than with testosterone.

Semen concentration rose to over 20×106 mL over the 16-week recovery period for the trestolone group, but azoospermia persisted in the testosterone group until 28 weeks had passed.

References

This section contains links to research, studies, and sources of information for this article, as well as authors, contributors, etc. All sources, along with the article and facts, are subjected to a series of quality, reliability, and relevance checks.

Real Muscle primarily uses high-quality sources, such as peer-reviewed publications, to back up the information in our articles. To understand more about how we fact-check and keep our information accurate, dependable, and trustworthy, read more about us.

This evidence-based analysis of trestolone features 13 references, listed below.

1. Nieschlag E, Kumar N, Sitruk-Ware R. 7α-methyl-19-nortestosterone (MENTR): the population council's contribution to research on male contraception and treatment of hypogonadism. Contraception. (2013)

2. J. Elks. The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. (14 November 2014)

3. Sundaram K, Kumar N, Bardin CW. 7 alpha-methyl-nortestosterone (MENT): the optimal androgen for male contraception. Ann Med. (April 1993)

4. Corona G, Rastrelli G, Vignozzi L, Maggi M. Emerging medication for the treatment of male hypogonadism. Expert Opin Emerg Drugs. (2012)

5. García-Becerra R, Ordaz-Rosado D, Noé G, Chávez B, Cooney AJ, Larrea F. Comparison of 7α-methyl-19-nortestosterone effectiveness alone or combined with progestins on androgen receptor mediated-transactivation. Reproduction. (2012)

6. Sinnesael M, Callewaert F, Morreels M, et al. 7α-methyl-19-nortestosterone vs. testosterone implants for hypogonadal osteoporosis: a preclinical study in the aged male orchidectomized rat model. Int J Androl. (2011)

7. LaMorte A, Kumar N, Bardin CW, Sundaram K. Aromatization of 7 alpha-methyl-19-nortestosterone by human placental microsomes in vitro. J Steroid Biochem Mol Biol. (1994)

8. Sundaram K, Kumar N, Bardin CW. 7 alpha-Methyl-19-nortestosterone: an ideal androgen for replacement therapy. Recent Prog. Horm. Res. (1994)

9. Liu A, Carlson KE, Katzenellenbogen JA. Synthesis of high affinity fluorine-substituted ligands for the androgen receptor. Potential agents for imaging prostatic cancer by positron emission tomography. J Med Chem. (1992)

10. Kumar N, Didolkar AK, Monder C, Bardin CW, Sundaram K. The biological activity of 7 alpha-methyl-19-nortestosterone is not amplified in male reproductive tract as is that of testosterone. Endocrinology. (1992) (Comparative Study)

11. Pike CJ, Carroll JC, Rosario ER, Barron AM. Protective actions of sex steroid hormones in Alzheimer's disease. Frontiers in Neuroendocrinology. (2009, Jul)

12. Walton, Melanie J., et al. 7α-methyl-19-nortestosterone (MENT) vs Testosterone in Combination With Etonogestrel Implants for Spermatogenic Suppression in Healthy Men. Journal of Andrology. (2007)

13. Kumar N, Suvisaari J, Tsong YY, et al. Pharmacokinetics of 7 alpha-methyl-19-nortestosterone in men and cynomolgus monkeys. J Androl. (1997)

✔ Citations with a tick indicate the information is from a trusted source.

The information provided in this article is not intended to replace professional medical advice, diagnosis, or treatment. Always seek the guidance of a physician or other competent professional before following advice or taking any supplement. See our terms and conditions.

We strictly do not advise anyone to use, or consider using, any exogenous hormone or chemical such as trestolone, unless advised or prescribed to do so by a qualified doctor. Doing so could result in serious and long-term adverse effects.