precisely what is Swiss Chems MK677 Ibutamoren? MK-677, often called ibutamoren or ibutamoren mesylate, is really a peptide that belongs to The expansion hormone secretagogues group (GHSR). It works by mimicking the action from the starvation hormone ghrelin. It binds to 1 of the growth hormone secretagogue receptors (GHSR) in the brain, serving to