SARMSARM

Andarine (S4)

SARM (S4)

Also known as S4, andarine, s-4

Half-life

~4-6 hours

What is Andarine (S4)?

Dry SARM with significant strength and hardening effects. Known for vision side effects in low light.

How Andarine (S4) works

Selective androgen receptor modulator with partial agonism in muscle/bone and less prostate stimulation than testosterone.

Benefits & uses

Lean muscle + hardness
Fat loss/endurance (with cardarine)
Milder androgenic profile

Common uses: Hardening, strength, recomposition, cutting.

Andarine (S4) 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: 25-50mg daily split AM/PM. Vision side effects (yellow tint) at higher doses — split dosing reduces this.
Commonly reported: Observational: ~25–75 mg/day (often split)Observational use reports — not a recommendation.

Andarine (S4) half-life

~4-6 hours

Andarine (S4) side effects

Yellow/green vision tint especially in dim light. Suppression.

Night-vision yellow tint
Suppression of endogenous testosterone
Lipid changes
🔴 VISION changes — yellow tint / difficulty adjusting to light (distinctive to S4, usually reversible)
Testosterone suppression
Lipid shift

Warnings & monitoring

Distinctive vision side effect (yellow tint, night-vision issues) — usually reversible on stopping
Suppressive — PCT may be needed
FDA-warned / WADA-banned / gray-market
Not approved for human use

Andarine (S4) interactions

with Ostarine
Compatible · low
S4 (Andarine) stacks well with Ostarine for cutting or recomposition. S4 provides anabolic hardening effects; Ostarine preserves muscle in a deficit. Vision side effects from S4 are dose-dependent.
Timing: Run concurrently; S4 may cause visual disturbances at higher doses

Commonly stacked with

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

Track Andarine (S4) in Protokol.

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