MK-677 (Ibutamoren) vs Melanotan II
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 →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 | MK-677 (Ibutamoren) | Melanotan II |
|---|---|---|
| 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. | 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 | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. | 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 | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. | Subcutaneous injection. Usually combined with UV exposure for tanning effects. Nasal spray formulations exist but have lower bioavailability. |
| 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. | Nausea (common initially), facial flushing, spontaneous erections, increased libido, appetite suppression, and mole darkening. |
| Best For |
What They Have in Common
Both MK-677 (Ibutamoren) and Melanotan II are commonly used for: