What is Swiss Chems MK677 Ibutamoren? MK-677, also referred to as ibutamoren or ibutamoren mesylate, is usually a peptide that belongs to The expansion hormone secretagogues team (GHSR). it really works by mimicking the motion on the hunger hormone ghrelin. It binds to at least one of the growth hormone secretagogue receptors (GHSR) in the brain, s