Andarine (S4)

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evidence score

sarm

Research Only

S4GTx-007andarine+1 more

Andarine (S4) is an arylpropionamide SARM developed by GTx Inc. for muscle wasting and osteoporosis. It has strong androgenic activity in muscle and bone with the unique property of producing significant fat loss alongside lean mass preservation — making it popular in cutting protocols. The defining and limiting characteristic is partial agonism at androgen receptors in the eye (retinal photoreceptors), causing a yellow/golden tint to vision and difficulty adjusting between light/dark environments, particularly at night. This side effect is dose-dependent and fully reversible. S4 has not proceeded to Phase III trials; clinical development was abandoned primarily due to the vision side effect.

Evidence

No score yet

Safety

Unknown safety profile

Clinical Status

No formal phase listed

Research Sync

Not synced yet

Dosing

Typical

50 mg

25 mgRange75 mg

Frequencydaily (split 2x/day due to half-life)

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Pharmacology

Half-life~3-4 hours

OnsetAnabolic effects 2-4 weeks; visual disturbances within first 1-2 weeks

DurationEffects and side effects present during use; vision normalizes 4-8 weeks post-cycle

Routes

oral

Evidence Score

—

0 studies indexed

Scoring Factors

Volume(40%)—

Quality(30%)—

Sample Size(10%)—

Consistency(10%)—

Replication(5%)—

Recency(5%)—

Evidence Levels

AScore ≥75 with at least 1 meta-analysis and 3+ RCTs

BScore ≥50 with at least 1 RCT or meta-analysis

CScore ≥25 — observational or animal evidence only

DScore <25 — very limited or preclinical data

Plain-English Snapshot

Andarine (S4) is currently categorized as a sarm compound.

Evidence scoring has not been fully computed yet, so interpret this profile as preliminary.

Safety scoring is incomplete. Start conservatively and monitor carefully.

Core mechanism

Full agonist at androgen receptor in muscle/bone; partial agonist at AR in prostate and eye; promotes nitrogen retention, protein synthesis; fat oxidation via beta-AR upregulation

Practical Context

Strongest current signals

No indexed study summaries yet.