MK-677 (Ibutamoren) occupies a unique position in GH-axis research as an orally bioavailable, non-peptide growth hormone secretagogue. While technically not a peptide, it acts on the same ghrelin receptor (GHS-R1a) as injectable GHRP peptides, making it functionally relevant to peptide research.
Research Applications
Clinical research areas: GH/IGF-1 axis stimulation (chronic oral dosing), sarcopenia and muscle wasting models, sleep architecture studies, bone mineral density research, and age-related GH decline.
Dosage Information (Research Use)
Published clinical trial doses: 10-25 mg once daily, oral administration, typically taken at bedtime. Duration up to 2 years in published studies. Research use only.
Reconstitution & Handling
N/A — MK-677 is an orally-active compound, not a reconstitutable peptide.
Half-Life & Pharmacokinetics
Approximately 24 hours, supporting once-daily oral administration. IGF-1 elevation persists throughout the 24-hour period.
Reported Observations in Literature
Published clinical data reports: increased appetite (pronounced), water retention, transient lethargy, numbness/tingling, elevated fasting glucose, and potential insulin resistance with chronic use.
Key Research References
- Murphy MG, et al. “MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism.” J Clin Endocrinol Metab. 1998
- Nass R, et al. “Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults.” Ann Intern Med. 2008