MK-677 (Ibutamoren) Tablets

Overview

MK-677 (Ibutamoren) is an orally active, non-peptide growth hormone secretagogue that mimics ghrelin at the GHS-R1a receptor. Despite being listed alongside peptides in vendor catalogs, it is technically a small molecule rather than a peptide. Its oral bioavailability and long half-life (24 hours) make it a convenient research tool.

Mechanism of Action

MK-677 activates the ghrelin receptor (GHS-R1a) in the pituitary and hypothalamus, stimulating GH release. Unlike peptide secretagogues, it is orally active and has a half-life permitting once-daily dosing. It elevates GH and IGF-1 levels in a sustained manner with maintained pulsatile patterns.

Research Context

Clinical studies have demonstrated MK-677's ability to increase GH secretion, elevate IGF-1 levels, improve sleep quality (particularly slow-wave sleep), and modify body composition in various populations including elderly subjects and those with GH deficiency.

Key Research Areas

Considerations for Researchers

Not a peptide -- classified as a small molecule ghrelin mimetic. Tablet form offers oral convenience. Appetite stimulation is a notable effect (ghrelin pathway). Limited vendor availability in tablet form.