Ibutamoren (MK-677)

Ibutamoren (MK-677) is an orally active growth hormone secretagogue that stimulates the body’s natural release of growth hormone (GH) and increases IGF-1 levels. Although commonly grouped with SARMs, Ibutamoren does not act on androgen receptors and is not a true SARM. In bodybuilding, it is primarily associated with muscle development, recovery, increased appetite and supporting lean muscle mass during bulking phases.

Ibutamoren acts as a ghrelin receptor agonist, stimulating growth hormone secretion without directly supplying growth hormone. Its intended effects include increased GH and IGF-1 signalling, improved recovery, support for muscle growth and potential improvements in sleep quality. Unlike androgen receptor modulators such as Ostarine or Ligandrol, MK-677 influences the growth hormone pathway rather than directly activating anabolic androgen receptors.