IMPORTANT: This page is for research/educational use only. Ensure correct handling, sterile technique (for injectables), and appropriate measurement. If you are unsure, consult qualified professionals.
MK-677 (Ibutamoren) (Oral)
MK-677 (ibutamoren) is a non-peptide ghrelin receptor (GHSR1a) agonist and growth hormone secretagogue that increases pulsatile growth hormone (GH) release and raises IGF-1 levels. It is studied for effects on body composition, sleep, recovery, and GH/IGF-1 axis physiology.
Dosing Protocols
- Common research dosing: 10–25 mg orally once daily, often taken in evening
- Cycle length: 8–16+ weeks with periodic lab monitoring (IGF-1, glucose, lipids)
- Consider washouts if adverse metabolic effects develop
Benefits
- Increases GH secretion and serum IGF-1
- May improve sleep architecture (in some studies)
- May increase lean body mass in certain populations
- Potential effects on bone turnover markers (context-dependent)
- Useful for studying ghrelin/GHSR signaling
Mechanism of Action
- Agonizes ghrelin receptor (GHSR1a) in hypothalamus/pituitary
- Increases GH pulse amplitude leading to increased hepatic IGF-1 production
- May increase appetite via hypothalamic pathways
- Can influence insulin sensitivity and glucose metabolism
Side Effects
- Increased appetite and weight gain
- Edema/water retention
- Lethargy or fatigue
- Increased fasting glucose/insulin resistance
- Joint pain/carpal tunnel-like symptoms
- Elevated blood pressure (possible)
- Numbness/tingling (fluid-related)
Side Effect Management
- Monitor fasting glucose and HbA1c; discontinue if glucose control worsens
- Use conservative dosing and consider intermittent protocols
- Manage appetite with structured diet; avoid surplus if weight gain undesired
- Monitor blood pressure and edema; adjust dose if swelling occurs
Contraindications
- Uncontrolled diabetes or significant insulin resistance
- Active malignancy (theoretical concern with IGF-1 elevation)
- Severe edema/heart failure
- Pregnancy/nursing
- Hypersensitivity
Research Citations
- Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults. J Clin Endocrinol Metab. PubMed | DOI
- Ibutamoren increases growth hormone and IGF-I in humans: endocrine and metabolic effects. J Clin Endocrinol Metab. PubMed | DOI
- Ghrelin receptor agonists and the GH axis: physiology and clinical potential. Nat Rev Endocrinol. PubMed | DOI
- MK-677 (ibutamoren) and sleep: effects on GH secretion and sleep architecture. Sleep. PubMed | DOI
IMPORTANT: This page is for research/educational use only. Ensure correct handling, sterile technique (for injectables), and appropriate measurement. If you are unsure, consult qualified professionals.
Research Use Only. All information on this page is for educational purposes only and is not medical advice. PepSherpa does not sell peptides. Consult a licensed healthcare provider before making any health decisions. Many of the studies cited are preclinical (animal/in-vitro).
Research Use Only. All information on this page is for educational purposes only and is not medical advice. PepSherpa does not sell peptides. Consult a licensed healthcare provider before making any health decisions. Many of the studies cited are preclinical (animal/in-vitro).
