What is Swiss Chems MK677 Ibutamoren? MK-677, also called ibutamoren or ibutamoren mesylate, is often a peptide that belongs to The expansion hormone secretagogues team (GHSR). it really works by mimicking the action in the starvation hormone ghrelin. It binds to at least one of the growth hormone secretagogue receptors (GHSR) during the brain, aid