MK 677 is a Growth-Hormone-Releasing-Hormone causes a release in Growth Hormone. It does this by mimicking the hormone ghrelin in the brain. Ghrelin is a key chemical in hunger.

One of the main benefits of MK-677, compared to other growth hormone releasing substances, is that it doesn’t affect cortisol levels. This is a huge advantage, because cortisol increases fat storage, anxiety and blood pressure. Ibutamoren does not have any of these unwanted effects.