MK-677 (Ibutamoren) vs Setmelanotide
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
MK-677 (Ibutamoren)
MK-677, also known as Ibutamoren, is an orally active growth hormone secretagogue. Unlike peptides, it can be taken orally and has a long half-life, providing 24-hour GH elevation.
Full details →Setmelanotide
Setmelanotide (Imcivree) is an FDA-approved MC4R agonist for chronic weight management in patients with obesity due to specific genetic conditions (POMC, PCSK1, or LEPR deficiency).
Full details →Side-by-Side Comparison
| Aspect | MK-677 (Ibutamoren) | Setmelanotide |
|---|---|---|
| Mechanism | Acts as a potent, selective agonist of the ghrelin receptor (GHS-R1a). Increases GH and IGF-1 levels without affecting cortisol. Mimics ghrelin's GH-releasing effects. | Selective agonist of melanocortin 4 receptors (MC4R) in the hypothalamus, restoring the satiety signaling pathway that is disrupted in certain genetic obesity syndromes. |
| Typical Dosage | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. | Adults: Start 2mg daily, titrate based on tolerability up to 3mg daily. Pediatrics (6+): Weight-based dosing starting at 1mg daily. |
| Administration | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. | Subcutaneous injection once daily. Requires genetic testing to confirm eligible mutations before prescribing. |
| Side Effects | Increased appetite and water retention are most common. May cause lethargy, vivid dreams, and mild numbness. Can affect blood glucose and insulin sensitivity. | Injection site reactions, skin hyperpigmentation, spontaneous penile erections, depression, and suicidal ideation (boxed warning). GI effects less common than GLP-1s. |
| Best For |
What They Have in Common
Both MK-677 (Ibutamoren) and Setmelanotide are commonly used for: