MK-677 (Ibutamoren)

Description

MK-677 (Ibutamoren)

MK-677 (Ibutamoren) is an oral growth hormone secretagogue designed to stimulate the body’s natural release of growth hormone (GH) and IGF-1 through ghrelin receptor activation. Unlike injectable GH peptides, MK-677 is taken as a once-daily capsule, making it popular for recovery, sleep optimization, lean muscle support, appetite stimulation, and body-recomposition research. It is widely recognized for increasing deep sleep quality, recovery signaling, and anabolic support without acting as a steroid or SARM.

Also known as: Ibutamoren, Nutrobal, L-163,191

•Status: Investigational – Phase II trials discontinued due to safety issues. Between 2025 and 2026, the FDA intensified enforcement actions, including product recalls, warning letters, and public safety notices highlighting the risk of congestive heart failure. Evidence based on human clinical trials.
•Standard dosage: 10–25 mg per day, taken orally once daily, typically at bedtime.
•Studied for potential use in increasing muscle mass, improving sleep, and stimulating appetite.