MK-677 (Ibutamoren) vs Retatrutide
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 →Retatrutide
Retatrutide is an investigational triple agonist targeting GIP, GLP-1, and glucagon receptors. Phase 2 trials showed unprecedented weight loss of up to 24% at 48 weeks, making it potentially the most effective obesity treatment studied.
Full details →Side-by-Side Comparison
| Aspect | MK-677 (Ibutamoren) | Retatrutide |
|---|---|---|
| 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. | Triple receptor activation provides complementary metabolic effects: GLP-1 and GIP reduce appetite and improve insulin sensitivity, while glucagon receptor activation increases energy expenditure and promotes hepatic fat oxidation. |
| Typical Dosage | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. | Clinical trials used doses from 1mg to 12mg weekly. Optimal dosing still being determined in ongoing Phase 3 trials. |
| Administration | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. | Subcutaneous injection once weekly. Currently only available through clinical trials - not yet FDA approved. |
| 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. | Similar GI effects to other incretin-based therapies: nausea, diarrhea, vomiting, constipation. Dose-dependent severity. |
| Best For |
What They Have in Common
Both MK-677 (Ibutamoren) and Retatrutide are commonly used for: