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S-23

Aliases: S23

Last verified: 2026-09-23

PreclinicalPreclinical evidenceSARMsLow interest

The short version

One of the most potent SARMs — closest to steroids in suppression; also studied as a male contraceptive (full spermatogenesis suppression in rats). Key fact: No controlled human trials exist. Everything known about S-23 in humans comes from indirect sources and self-reports. Status: preclinical. Not approved; WADA-banned (S1).

Identity & type

Molecular type
SARM
Origin
One of the most potent SARMs — closest to steroids in suppression; also studied as a male contraceptive (full spermatogenesis suppression in rats).

Mechanism of action

High-affinity full AR agonist in muscle/bone.

not confirmed in humans

Dosing & routes

Official / clinical context

No approved official document exists for S-23. Any protocols mentioned are to be read as information, not as a recommendation.

Regulator-approved labeling and published study designs — never a recommendation.

Community-reported practice

Community: 10–30 mg/day split (short half-life). The community describes it as "closest to steroids": pronounced growth and dryness, but strong suppression and sometimes aggression; cycles are kept short.

Unverified self-reports. Not medical advice. Not endorsement.

Expected effects (community)

The community describes it as "closest to steroids": pronounced growth and dryness, but strong suppression and sometimes aggression; cycles are kept short.

Protocol — official vs community

Official / label

No official protocol exists — this compound has no approved product.

Community (anecdotal)

10–30 mg oral daily, split into two doses because of the short half-life.

Cycle:
8 weeks, sometimes shorter at the high end of the dose range.
Break:
Full SERM-based PCT is treated as mandatory, not optional, given the suppression depth.

The community consensus is that S-23 is the SARM closest to a steroid in effect and in suppression — it was a male-contraceptive candidate in rats. Cycles are kept short and PCT aggressive accordingly.

Human evidence

No controlled human trials exist. Everything known about S-23 in humans comes from indirect sources and self-reports.

Preclinical evidence

Preclinical only (GTX).

Known risks

  • Marked HPTA suppression, aggression, lipid changes; no human safety data.characterized
  • WADA prohibition (S1 anabolic agents)characterized

Teal: characterized in clinical/labeling contexts. Amber: theoretical or reported outside controlled settings.

Unknowns & evidence gaps

  • All human pharmacokinetics, safety and efficacy

Frequently asked questions

References

Systematic references are being expanded; verify sources directly before any decision.