What is Swiss Chems MK677 Ibutamoren? MK-677, often known as ibutamoren or ibutamoren mesylate, is often a peptide that belongs to the growth hormone secretagogues team (GHSR). It works by mimicking the motion of the starvation hormone ghrelin. It binds to 1 of the growth hormone secretagogue receptors (GHSR) within the brain, aiding increase advan