What is Swiss Chems MK677 Ibutamoren? MK-677, often known as ibutamoren or ibutamoren mesylate, is usually a peptide that belongs to the growth hormone secretagogues team (GHSR). It works by mimicking the action on the hunger hormone ghrelin. It binds to 1 of the growth hormone secretagogue receptors (GHSR) during the brain, assisting enhance advan