SARMSARM

S-23

SARM (high potency)

Also known as S23, s23

Half-life

~11-12 hours

What is S-23?

High-potency investigational SARM with strong suppressive activity.

How S-23 works

Potent AR agonism in muscle/bone with marked gonadotropin suppression in preclinical models.

Benefits & uses

Very potent muscle/strength
Dry/hard gains
Reputation as strongest SARM

Common uses: Advanced muscle/strength (experimental).

S-23 dosage

Protokol doesn't recommend doses for prescription or controlled compounds. Any figures below are reference or observational reports — dosing should be set with a qualified clinician.

Protocol notes: 10-20mg daily. Most suppressive SARM — causes temporary infertility at higher doses. Strongest SARM for body recomposition.
Commonly reported: Observational only; experimentalObservational use reports — not a recommendation.

S-23 half-life

~11-12 hours

S-23 side effects

Severe HPT suppression
Mood/libido disruption
Lipid deterioration
🔴 Very strong testosterone suppression (studied as a male contraceptive)
Lipid shift
Aggression/mood
Hair loss/acne

Warnings & monitoring

🔴 Among the most suppressive SARMs — significant shutdown, aggressive PCT needed. Bloodwork + medical monitoring
Experimental, minimal human data
FDA-warned / WADA-banned / gray-market
Not approved for human use

Commonly stacked with

Cardarine (GW-501516)Ostarine (MK-2866)

Track S-23 in Protokol.

Log doses, model half-lives, check interactions, and line it all up against your bloodwork. Free on iPhone and Android.