What is Swiss Chems MK677 Ibutamoren? MK-677, often known as ibutamoren or ibutamoren mesylate, is a peptide that belongs to the growth hormone secretagogues group (GHSR). it really works by mimicking the motion on the starvation hormone ghrelin. It binds to 1 of the growth hormone secretagogue receptors (GHSR) inside the brain, encouraging increas