MK-677: Research Overview and Mechanism
MK-677 (Ibutamoren) is a non-peptide small molecule studied in laboratory and preclinical research as an orally active agonist of the growth hormone secretagogue receptor within GH/IGF-1 axis models. Unlike the peptide secretagogues, it is a small molecule rather than a lyophilized peptide. It is for research use only and is not approved for human use.
What MK-677 is
MK-677, also known as Ibutamoren, is a non-peptidic small molecule that acts as an agonist of the growth hormone secretagogue receptor, the same receptor targeted by the peptide secretagogues. Its free-base molecular weight is near 529 g/mol.
Its distinguishing feature in research literature is that it is orally active and is a small molecule rather than a peptide, which sets it apart from compounds such as GHRP-2, GHRP-6, and Ipamorelin and makes it a point of interest in secretagogue-pharmacology research. The research material is often supplied as the mesylate salt, which has a different molecular weight and CAS than the free base.
Pathways it is studied within
In laboratory and preclinical research, MK-677 is studied for GHS-R (ghrelin) receptor agonism, the GH/IGF-1 axis, oral-secretagogue behavior, and secretagogue pharmacology. It is a non-peptide agonist of the same Gq-coupled GHS-R1a receptor engaged by the peptide secretagogues, but its small-molecule structure confers oral bioavailability and a longer duration of action in research models, the property that sets it apart from GHRP-2, GHRP-6, and Ipamorelin; that peptide-versus-small-molecule contrast is treated in full in our MK-677 vs Ipamorelin comparison.
MK-677 (Ibutamoren), originally developed by Merck, also has an extensive published human clinical-trial history as an orally active growth hormone secretagogue, including investigational studies in older adults, and it reached advanced clinical development without receiving regulatory approval for any indication. That clinical-literature and regulatory context is reported here in the third person as public fact about the molecule and does not describe this product, which is supplied for research use only and is not approved for human use.
Handling and documentation
Because MK-677 is a small molecule rather than a lyophilized peptide, it is supplied as a powder and prepared per the research protocol rather than reconstituted like a peptide. Store at -20C protected from light and moisture. Every batch is doctoral chemist tested and ships with a lot-matched Certificate of Analysis; confirm the exact salt form (free base versus mesylate) against that document before using the molecular-weight value in research.
All products are intended strictly for in-vitro laboratory research and development use only. Not for human or veterinary use, not a drug, food, or cosmetic, and not intended to diagnose, treat, cure, or prevent any disease.