Ibutamoren (MK-677)

Ibutamoren (INN) (developmental code names MK-677, MK-0677, L-163,191; former tentative brand name Oratrope) 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.[3][4][5][6][7] 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.[8]

 

Ibutamoren has been shown to sustain activation of the GH–IGF-1 axis and to increase lean body mass with no change in total fat mass or visceral fat. It is under investigation as a potential treatment for reduced levels of these hormones, such as in children or elderly adults with growth hormone deficiency,[3][9][10][11] and human studies have shown it to increase both muscle mass and bone mineral density,[12][13] making it a promising potential therapy for the treatment of frailty in the elderly.[14][15] As of June 2017, ibutamoren is in the preclinical stage of development for growth hormone deficiency.[3]