Exceptional purity for peptide research
We've been sourcing research-grade peptides for several years. Rainbow Peptide's vials consistently pass our HPLC verification — purity exceeds 98% every batch. COA matched our internal testing exactly.
MK-677 (Ibutamoren) powder 1g — ≥98% HPLC purity, COA verified. Orally active ghrelin receptor agonist and GH secretagogue studied in GH deficiency, muscle wasting, and metabolic research. For research use only.
In Stock — Overnight and 2–3 day delivery available
MK-677 (Ibutamoren, L-163,191) is an orally active, non-peptide ghrelin receptor (GHSR-1a) agonist that stimulates pulsatile growth hormone secretion and sustained IGF-1 elevation. Unlike GHRH analogues or GHRPs, MK-677 is orally bioavailable with a long half-life (~24 hours in humans), making it pharmacologically distinct for research into GH axis restoration.
MK-677 mimics the endogenous ghrelin ligand at the GHSR-1a receptor in the hypothalamus and pituitary, stimulating GH release. Unlike exogenous GH, it preserves the pulsatile pattern of GH secretion, which is physiologically important for downstream IGF-1 production, anabolic signalling, and metabolic effects. Chronic administration maintains GH and IGF-1 elevation without pituitary desensitisation in rodent models.
Raw powder is suited for formulation research (oral suspension, solution), in vitro receptor assays, and pharmacokinetic studies. MK-677 is soluble in DMSO (≥50mg/mL) and ethanol. For in vivo rodent studies, it is typically administered in drinking water or oral gavage at 10–25mg/kg/day.
Published research areas include: GH deficiency modelling, sarcopenia and muscle wasting, sleep architecture (MK-677 increases slow-wave sleep duration), bone mineral density, and cognitive performance in IGF-1-sensitive neural circuits.
Purity: ≥98% (HPLC verified) | Format: Lyophilised powder | Quantity: 1g
For research use only. Not for human consumption.
Third-Party Verified
We don't just claim purity — we prove it. Every batch of MK-677 Powder 1g is independently tested by an accredited third-party laboratory before it reaches you. Your COA is linked to your specific lot number.
Verified purchases from active research labs and scientists
We've been sourcing research-grade peptides for several years. Rainbow Peptide's vials consistently pass our HPLC verification — purity exceeds 98% every batch. COA matched our internal testing exactly.
Third order now. Consistent batch-to-batch results matter enormously in long-term research. Certificate of Analysis is detailed with mass spec data. Would not switch sources.
Verified against our reference standards. Purity >98.2% by HPLC. Packaging was appropriate for temperature-sensitive peptides. Will re-order.