Ibutamoren (MK-677, L-163,191) is a drug which acts as a potent, orally active growth hormonesecretagogue, mimicking the GH stimulating action of the endogenous hormone ghrelin. It has been demonstrated to increase the release of, and produces sustained increases in plasma levels of several hormones including growth hormone and IGF-1, but without affecting cortisol levels. It is currently under development as a potential treatment for reduced levels of these hormones, such as in growth hormone deficient children or elderly adults, and human studies have shown it to increase both muscle mass and bone mineral density, making it a promising therapy for the treatment of frailty in the elderly. It also alters metabolism of body fat and so may have application in the treatment of obesity.
MK677, otherwise known as Ibutamoren is a Growth Hormone secretagogue, it was researched and developed for the pharmacological treatment of various diseases such as MS, obesity ,GH deficiency and osteoporosis.
Ibutamoren has been shown to sustain activation of the GH–IGF-1 axis and to increase lean body mass with no change in total fat mass or visceral fat. It is under investigation as a potential treatment for reduced levels of these hormones, such as in children or elderly adults with growth hormone deficiency, and human studies have shown it to increase both muscle mass and bone mineral density,making it a promising potential therapy for the treatment of frailty in the elderly. As of June 2017, ibutamoren is in the preclinical stage of development for growth hormone deficiency.
Since MK-677 is still a Investigational New Drug, it has not yet been approved to be marketed for consumption by humans in the United States. However, it has been used experimentally by some in the bodybuilding community. Since it chemically mimics the hormone ghrelin, it functions as a neuropeptide in the central nervous system and crosses the blood-brain-barrier. According to some recent research and discussion, there is a concern that its particularly longer half-life might over-stimulate the ghrelin receptors in the brain and lead to some harmful mental side effects.