S-4 Reference

Plain English

What it is

S-4, also called andarine, is a SARM, which is a lab-made drug that targets the body's muscle-building hormone signals. It is sold as a research chemical, not as an approved medicine, and there is no FDA-approved S-4 drug.

What people use it for

In bodybuilding and fitness circles, people talk about S-4 for cutting and recomposition goals, meaning getting leaner while trying to hold onto muscle. This is anecdotal community use and is not an approved or proven use.

What the science shows

Published research on S-4 is mostly animal and preclinical work, with only small, early-stage human exposure. The drug company that developed it ran an early-phase human trial but stopped its development after vision problems showed up. No real study program exists for using it to reshape the body.

The catch

The FDA warns the public against SARMs, which are sold illegally and are often mislabeled, and links them to risks like lowered natural testosterone, liver strain, worse cholesterol, and a higher chance of heart attack or stroke. Sports anti-doping bodies (WADA) ban all SARMs at all times as S1.2 anabolic agents. S-4's signature problem is a yellow or blue tint to vision and trouble adjusting to dim light, the very effect that helped end its human trials.

Reference summary

Published work is preclinical and small early-phase human exposure. No outcome program for body-composition use exists.

Regulatory and posture

Categories

SARM, Fat Loss

Aliases

Andarine, GTx-007, Non-steroidal SARM

Evidence posture

preclinical - FDA enforcement attention. Sold only as a research chemical, not for human consumption per legal seller terms. WADA-prohibited under category S1.2 at all times. Visual disturbances (yellow / blue tint, dim-light adaptation) are widely reported and have led to discontinuation in human trials. No FDA-approved drug label.

Regulatory status

No FDA-approved S-4 drug label. WADA prohibits SARMs under category S1.2 at all times. FDA enforcement against SARMs sellers applies. Community accounts report distinctive yellow / blue visual disturbances at active doses.

Content review status

research reference