what on earth is Swiss Chems MK677 Ibutamoren? MK-677, also called ibutamoren or ibutamoren mesylate, can be a peptide that belongs to the growth hormone secretagogues group (GHSR). it really works by mimicking the action of your hunger hormone ghrelin. It binds to one of The expansion hormone secretagogue receptors (GHSR) in the brain, helping max