MK-0773 Reference

Plain English

What it is

MK-0773 is a SARM, which is a lab-made drug that targets the body's muscle-building hormone signals. It was created by a drug company to study muscle loss, and today it is sold only as a research chemical, not as an approved medicine.

What people use it for

In the bodybuilding and body-recomposition community, some people have been interested in it to gain muscle or change their body shape. This interest is anecdotal and is not an approved use, and real-world use of MK-0773 is actually rare because the program was abandoned.

What the science shows

MK-0773 reached a small, early human trial in older women who were losing muscle, so there is real human data, not just animal studies. It did raise lean muscle mass, but it did not make people stronger or improve how their bodies worked. Because of that, and because of safety concerns, the developers stopped working on it.

The catch

The U.S. FDA has warned the public against SARMs, which are sold illegally, are often mislabeled, and are not approved as safe, while the World Anti-Doping Agency bans them in sport at all times as anabolic agents (class S1.2). In its human trial, MK-0773 raised liver enzymes, a sign of liver strain, which eased after people stopped it, and SARMs as a group are also linked to cholesterol and heart-related effects. There is no claim here that MK-0773 is a federally scheduled controlled substance.

Reference summary

Phase 2 sarcopenia trial in postmenopausal women showed lean-mass improvements without functional-outcome benefit; the program was discontinued.

Regulatory and posture

Categories

SARM

Aliases

Non-steroidal SARM, Merck Phase 2 sarcopenia investigational

Evidence posture

human - 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. Phase 2 in sarcopenia did not advance - Merck discontinued the program. No FDA approval followed.

Regulatory status

No FDA-approved MK-0773 drug label. WADA prohibits SARMs under category S1.2 at all times. FDA enforcement against SARMs sellers applies. Merck advanced MK-0773 to Phase 2 sarcopenia trials, then discontinued the program.

Content review status

research reference