MK-677, LGD-4033, and MK-2866 is a Growth Hormone Secretagogue which means that it is a compound that stimulates the pituatary gland to increase production of Human Growth Hormone (HGH) and does not cause pituatary desensitization. When HGH enters the blood stream it converts to IGF-1 (Insulin Like Growth Factor).

 This is Responsible for Muscle Growth, IGF-1 Binds to its receptors in skeletal muscle tissue accelerating Protein Synthesis.

Another Unique Feature of Growth hormone is Hyperplasia, the increases in the number of muscle cells to their prolife- ration. This Effect is Significant because HGH induces muscle gains are permanent and divided cells allow you to exceed your Genetic limit for muscle mass.