Head to head
Enobosarm against Testosterone
The selectivity argument, tested. SARMs were designed to act on muscle and bone without the prostate and cardiovascular effects of testosterone; testosterone has the 5,246 man randomised safety trial and enobosarm has no approval for any use.
Column A
EnobosarmEnobosarm (ostarine, GTx-024, MK-2866)
The selective androgen receptor modulator known on the gray market as ostarine, now in formal trials where 3 mg cut lean-mass loss on semaglutide by 71% in adults over 60.
Column B
TestosteroneTestosterone, the principal androgen
The best-evidenced hormone on this site. A 5,246-man randomised trial settled the cardiovascular question, and 36 randomised trials in 8,480 women cover the half of the population nobody talks about.
Side by side, on the facts we can check
| Attribute | Enobosarm | Testosterone |
|---|---|---|
| Category | Muscle & Performance | Hormone |
| FDA status | Investigational; not approved for any use. Unapproved SARM products are illegal to sell as supplements. | FDA-approved for male hypogonadism in multiple formulations. Schedule III controlled substance in the United States. No testosterone product is approved for women in the United States, which is a documented gap rather than a judgement on the evidence. |
| Half-life | ~24 hours (once-daily oral) | Free testosterone itself clears in minutes to hours. What determines dosing is the ester: cypionate and enanthate run roughly eight days, propionate under a day, and undecanoate several weeks. The ester pages cover what that means in practice. |
| Molecular weight | 389.3 Da | 288.4 Da. A steroid, not a peptide. |
| Mechanism | Tissue-selective androgen receptor agonism that promotes muscle protein synthesis with less androgenic effect on prostate and skin than testosterone. | A 19-carbon steroid synthesised from cholesterol, mainly in the Leydig cells of the testis under luteinising hormone control, and in smaller amounts by the ovary and adrenal in women. It acts directly on the androgen receptor, a nuclear receptor that binds DNA and alters transcription. Two conversions matter clinically: 5-alpha-reductase converts it to dihydrotestosterone, a more potent androgen responsible for much of the effect on scalp hair and prostate, and aromatase converts it to oestradiol, which is responsible for much of its effect on bone, mood and libido in men. Exogenous testosterone suppresses luteinising hormone and follicle-stimulating hormone through negative feedback, which is why it reduces sperm production and testicular size. |
| Human studies cited | 3 | 2 |
| Legal status, US | Investigational; SARMs are not legal dietary ingredients and are on the WADA prohibited list | FDA-approved, prescription only |
Frequently asked questions
What is the difference between Enobosarm and Testosterone?
Enobosarm: The selective androgen receptor modulator known on the gray market as ostarine, now in formal trials where 3 mg cut lean-mass loss on semaglutide by 71% in adults over 60. Testosterone: The best-evidenced hormone on this site. A 5,246-man randomised trial settled the cardiovascular question, and 36 randomised trials in 8,480 women cover the half of the population nobody talks about.
Which has stronger research evidence, Enobosarm or Testosterone?
This database does not grade compounds. It counts what was run in people: 3 of the 3 studies cited on the Enobosarm profile were human work, against 2 of 5 for Testosterone. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are Enobosarm and Testosterone FDA-approved?
Enobosarm: Investigational; not approved for any use. Unapproved SARM products are illegal to sell as supplements.. Testosterone: FDA-approved for male hypogonadism in multiple formulations. Schedule III controlled substance in the United States. No testosterone product is approved for women in the United States, which is a documented gap rather than a judgement on the evidence..
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.