MK-677 (also known as ibutamoren), promotes the secretion of the growth hormone (GH) and increases insulin-like growth factor 1 (IGF-1). Ibutamoren increases growth hormone levels by mimicking the action of the hormone ghrelin and binding to one of the ghrelin receptors (GHSR) in the brain. Activated GHSR stimulates growth hormone release from the brain. Clinical studies describe only the effects ibutamoren has on appetite and as expected, like ghrelin, ibutamoren increases it. GHSR is found in brain regions that control appetite, pleasure, mood, biological rhythms, memory, and cognition.