what on earth is Swiss Chems MK677 Ibutamoren? MK-677, generally known as ibutamoren or ibutamoren mesylate, is usually a peptide that belongs to the growth hormone secretagogues group (GHSR). It works by mimicking the action of the starvation hormone ghrelin. It binds to 1 of The expansion hormone secretagogue receptors (GHSR) while in the Mind, a