Ibutamoren (developmental code names MK-677, MK-0677, L-163,191) is a potent, long-acting, orally-active, selective, and non-peptide agonist of the ghrelin receptor and a growth hormone secretagogue, mimicking the growth hormone (GH)-stimulating action of the endogenous hormone ghrelin. 

It has been shown to increase the secretion of several hormones including GH and insulin-like growth factor 1 (IGF-1) and produces sustained increases in the plasma levels of these hormones without affecting cortisol levels. Ibutamoren can help increase muscle growth, burn fat and improve recovery. Those who use SARMs and SARM-like compounds commonly follow 8 week cycles for lean muscle gain and strength enhancement then take the following 8 weeks off. Ibutamoren works well at lower doses. An average dose of 5mg daily produces optimal fat loss and muscle growth.