SARMs
S-23
A SARM investigated for hormonal male contraception in rats, with suppression of reproductive hormones and sperm production rather than human contraceptive evidence.
Rat reproductive study with a combination intervention; no human contraceptive validation
Practical use
Evidence interpretation and clinical context
- Retain the full experimental context
- Name the combination and species when discussing fertility findings.
- Treat recovery as an outcome
- A rat follow-up observation does not supply a human recovery promise.
- Do not confuse goals
- A contraceptive-development result is not evidence for a performance-enhancement regimen.
Overview
S-23 is an androgen-receptor agonist studied for anabolic effects and male contraception. The contraceptive experiment used S-23 with estradiol benzoate in rats, making attribution to S-23 alone inappropriate.
Risks and limitations
Reproductive suppression was an intended effect in this research. Animal recovery after an experimental intervention does not establish predictable fertility recovery in people or a safe performance-enhancement practice.
How to read this
An anabolic response and suppression of the reproductive axis can coexist. Calling a compound selective does not mean its endocrine effects are limited to muscle.
Research explained
Preclinical characterization of a (S)-N-(4-cyano-3-trifluoromethyl-phenyl)-3-(3-fluoro, 4-chlorophenoxy)-2-hydroxy-2-methyl-propanamide: a selective androgen receptor modulator for hormonal male contraception.
Who was studied
Male rats in androgenic/anabolic assays and a hormonal-contraception experiment that included estradiol benzoate.
What was found
S-23 suppressed gonadotropins. In the studied combination group, sperm production was markedly suppressed and mating did not produce pregnancies; fertility returned during follow-up in the experimental setting.
What it cannot establish
The reproductive findings came from rats and a combination intervention. Neither human contraception nor a human recovery timeline was established.
Read the original studyRegulatory status
FDA states that SARMs are unapproved drugs, not dietary supplements.
Supporting sourceThe co-intervention matters
Estradiol benzoate was part of the contraceptive experiment. Removing it from a summary misrepresents what investigators tested.
Supporting sourceClaims versus findings
Not supported
The rat study establishes reversible human contraception with S-23 alone.
It tested rats and included another hormone; species, intervention and recovery findings cannot be transferred directly.
Check the evidenceCommon questions
Does anabolic activity mean fertility is protected?
No. The study investigated anabolic activity alongside suppression of reproductive signaling.
SourceSources
Regulatory status — primary or official source
Sources checked 2026-10-01.
General education; not a personal treatment plan.