MK-677 Peptide Research
MK-677 is a non-peptide ghrelin receptor agonist studied for GH and IGF-1 stimulation.
ghrelin receptor agonist
Clinical
research maturity
Overview
MK-677, also known as ibutamoren, is an orally active ghrelin receptor agonist developed to stimulate endogenous growth hormone release without direct GH injection. It has real human clinical data, but it is not FDA approved.
Primary goals
Comparisons
Related stacks
Performance Stack
GH Optimization Stack
Ghrelin Drive Stack
Mechanism
It activates the ghrelin receptor, increasing pulsatile growth hormone secretion and raising circulating IGF-1. This links it to endocrine, sleep, and body-composition research rather than direct GH replacement.
Clinical interest
Clinical interest centers on hormone optimization, body recomposition, sleep architecture, aging-related catabolism, and GH-axis support. It is usually discussed as an oral alternative to injectable secretagogues, though that does not make it clinically interchangeable with approved therapies.
Research summary
Human trials show that MK-677 can increase GH and IGF-1, improve sleep measures, and increase fat-free mass in some populations. The evidence is materially stronger than for many gray-market peptides, but still much weaker than for approved endocrine or obesity drugs.
Safety considerations
Relevant concerns include appetite increase, edema, insulin sensitivity changes, elevated glucose in some users, and overstatement of body-composition effects. It should not be framed as a benign shortcut.
Key information
Research stage
Clinical
Evidence rating
Moderate
Search intent
informational
Last review
Mar 13, 2026
Featured studies
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7
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Frequently asked questions
What is MK-677?
MK-677 is an oral ghrelin receptor agonist studied for increasing endogenous growth hormone and IGF-1 levels.
Is MK-677 the same as growth hormone?
No. MK-677 stimulates the body to release more GH, while somatropin is direct recombinant human growth hormone.