MK-677 (Ibutamoren): Scientific Profile

Publicado el 25 de julio de 2026 · Actualizado el 29 de agosto de 2026

Non-peptide growth hormone secretagogue, ghrelin receptor (GHS-R1a) agonist, orally active.

MK-677, also known as Ibutamoren (English name Ibutamoren; development code MK-0677; CAS 159752-10-0), is a synthetic NON-peptide compound, orally administered, that acts as a growth hormone secretagogue. With molecular formula C27H36N4O5S and an approximate molecular weight of 528.66 g/mol, it is a small molecule that, unlike GH-releasing peptides, is stable against digestion and orally active in research models.

MK-677's mechanism of action is based on agonism of the growth hormone secretagogue receptor (GHSR-1a), which is the same receptor on which endogenous ghrelin acts. By mimicking ghrelin signaling, in preclinical models a pulsatile increase in growth hormone (GH) secretion from the pituitary has been described and, secondarily, an increase in insulin-like growth factor 1 (IGF-1) levels. A feature of experimental interest is that this stimulus tends to preserve the pulsatile nature of GH secretion and does not markedly suppress the endogenous axis in the models studied.

In the research setting, MK-677 is used as an oral tool for studying the GH/IGF-1 axis, ghrelin signaling, and their effects on metabolism, body composition, and sleep in experimental models. Its oral bioavailability and relatively long half-life make it convenient for once-daily dosing protocols in research.

MK-677 is supplied in the presentation indicated for its stable storage. Keeping it protected from light and moisture according to the protocol is recommended. This product is offered exclusively as a research reagent (research use only): it is not intended for the diagnosis, prevention or treatment of any disease, nor for human or veterinary consumption.