Retatrutide vs Melanotan II
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
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 →Melanotan II
Melanotan II is a synthetic peptide analog of α-MSH with broader receptor activity than Melanotan I. It produces tanning effects and has notable effects on sexual function and appetite suppression.
Full details →Side-by-Side Comparison
| Aspect | Retatrutide | Melanotan II |
|---|---|---|
| Mechanism | 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. | Non-selective melanocortin receptor agonist affecting MC1R (tanning), MC3R and MC4R (sexual function and appetite). This broader activity explains its multiple effects beyond tanning. |
| Typical Dosage | Clinical trials used doses from 1mg to 12mg weekly. Optimal dosing still being determined in ongoing Phase 3 trials. | Typical protocols: 0.25-0.5mg daily during loading phase for 1-2 weeks, then 0.5-1mg before UV exposure for maintenance. Start low to assess tolerance. |
| Administration | Subcutaneous injection once weekly. Currently only available through clinical trials - not yet FDA approved. | Subcutaneous injection. Usually combined with UV exposure for tanning effects. Nasal spray formulations exist but have lower bioavailability. |
| Side Effects | Similar GI effects to other incretin-based therapies: nausea, diarrhea, vomiting, constipation. Dose-dependent severity. | Nausea (common initially), facial flushing, spontaneous erections, increased libido, appetite suppression, and mole darkening. |
| Best For |
What They Have in Common
Both Retatrutide and Melanotan II are commonly used for: