Meta Black Mk-677 is a Growth Hormone Secretagogue which means that it is a compound that stimulates the pituitary gland to increase the production of human growth hormone and does not cause pituitary desensitization.
Another unique feature of growth hormone is hyperplasia, the increase in the number of muscle cells due to their proliferation.
This effect is significant because HDH-induced muscle gains are permanent, and divided cells allow you to exceed your genetic limit for muscle mass.
The fat-burning function of HGH is performed by the growth hormone itself.
The hormone binds to somatropin receptors, which leads to an elevation of the level of free fatty acids. So the body starts using fat, instead of carbohydrates, as an energy source.