Explore S4 dosage trends, reconstitution volumes, and vial size patterns from anonymized WPA peptide calculator data.
S4 (andarine) is a first-generation SARM — a small molecule, not a peptide — sourced in research for muscle and bone studies. It is sold as a research chemical (capsules or an oral liquid).
S4 binds the androgen receptor as a tissue-selective partial agonist with reported preference for muscle and bone over prostate.[1][3] It is unusual within the SARM class for its prominent ocular side-effect signal: users and case reports consistently describe yellow-tinged vision and reduced low-light visual adaptation at consumer doses, attributed to S4 binding to a receptor in the visual cycle.[4] These effects are typically reversible on discontinuation but are sufficiently common that they distinguish S4 from other SARMs in consumer safety reporting.
The pre-clinical pharmacology of S4 was published by Gao and colleagues in the early GTx SARM program.[3] No registered Phase 2 or Phase 3 human trial of S4 has been conducted; the molecule was overtaken in the GTx pipeline by enobosarm. Consumer-grade S4 use has accumulated published case reports of visual disturbance and at least one report of severe vision impairment requiring medical evaluation.[4][5] As with other SARMs, drug-induced liver injury has been reported in the broader SARM-class case-report literature, though S4-specific DILI reports are less common than for RAD-140 or LGD-4033.[6]
Not FDA-approved. No registered Phase 2/3 trial; pre-clinical only. WADA-prohibited at all times. Documented case reports of ocular toxicity. Research-grade material only.
S4 has a reported half-life of ~4 hours (pre-clinical estimate). The pharmacokinetic reference models an interval of two to three times daily; this is not a measured community cadence or a dosing recommendation. A short half-life is why andarine is typically split into multiple daily doses — a single daily dose would leave long troughs. Levels clear substantially between doses. Pharmacokinetic source: Pre-clinical (animal) data only (andarine); not characterised in humans. It is catalogued under Other Peptides on WPA.
The WPA community has not yet logged enough S4 calculator sessions to publish dose, vial size, or bacteriostatic water distributions for it. This page therefore covers what is known about the compound itself; the usage charts fill in as researchers run the calculator.
These figures come from anonymized WPA peptide calculator sessions, not verified administrations or unique people. Separate modal inputs do not establish a joint protocol. They are community input statistics — not dosing recommendations, and not medical advice.
These figures come from anonymized WPA peptide calculator sessions.
All figures shown are aggregated from anonymized calculator inputs and are provided strictly for independent laboratory research and educational purposes. They are community usage statistics — not dosing recommendations, and not medical advice.