MK-677: What It Is, What the Research Says, and What You Need to Know

An oral growth hormone secretagogue — one of the few that doesn't require injection

Last updated: May 1, 2026

MK-677 is technically not a peptide — it is a small molecule that mimics ghrelin (the 'hunger hormone') to stimulate GH release from the pituitary. It is commonly discussed alongside peptides in research and biohacking communities.

Its most notable feature is oral bioavailability. Most GH-releasing compounds must be injected because they are destroyed in the digestive tract. MK-677 remains active when taken orally.

It was originally developed by Merck for conditions like muscle wasting, osteoporosis, and growth hormone deficiency, but was never brought to market for these indications.

• Human trials show MK-677 significantly increases GH pulse amplitude and IGF-1 levels.
• A 2-year trial in elderly adults showed increased lean mass and reduced fat mass.
• Studies in hip fracture patients showed improved recovery and muscle strength.
• Ongoing research for Alzheimer's disease (based on its effects on sleep architecture).
• Concerns raised in one study about insulin resistance with long-term use.

These reflect how researchers and research communities discuss this compound — not therapeutic recommendations.

• GH optimization without injections
• Muscle mass and recovery research
• Bone density improvement
• Sleep quality improvement

Binds to the ghrelin receptor (GHSR) in the pituitary and hypothalamus, stimulating GH release. Its oral bioavailability and long half-life (~24 hours) distinguish it from injectable GH secretagogues.