What is Swiss Chems MK677 Ibutamoren? MK-677, generally known as ibutamoren or ibutamoren mesylate, is actually a peptide that belongs to The expansion hormone secretagogues group (GHSR). it really works by mimicking the motion in the hunger hormone ghrelin. It binds to 1 of the growth hormone secretagogue receptors (GHSR) inside the brain, helping