Source comparison
Melanotan-2 Libido Complete Guide 2026: Comparison of Melanocortin Agonists
| Peptide | Primary Receptor Target | Onset Time (Subcutaneous) | Duration of Libido Effect | Published Clinical Efficacy (Spontaneous Erection Rate) | Notable Side Effects | Professional Assessment ||—|—|—|—|—|—|| Melanotan-2 | MC4R, MC3R, MC1R, MC5R | 2–4 ho
This comparison does not assign a generated winner or score.
- | Peptide | Primary Receptor Target | Onset Time (Subcutaneous) | Duration of Libido Effect | Published Clinical Efficacy (Spontaneous Erection Rate) | Notable Side Effects | Professional Assessment ||—|—|—|—|—|—|| Melanotan-2 | MC4R, MC3R, MC1R, MC5R | 2–4 hours | 6–12 hours | 80% in psychogenic ED (Wessels et al., 2000) | Nausea, flushing, darkened skin, spontaneous erections | Most potent central libido agonist; nonselective receptor binding causes tanning and nausea alongside sexual effects || PT-141 (Bremelanotide) | MC4R, MC3R (selective) | 45–90 minutes (subcutaneous) | 4–8 hours | 52% improvement in female sexual desire (FDA HSDD approval) | Nausea (40% incidence), headache, flushing | FDA-approved for female HSDD; avoids MC1R so no tanning; shorter onset than MT-2 || Sildenafil (Viagra) | PDE5 inhibitor (vascular) | 30–60 minutes (oral) | 4–6 hours | 70–80% in vascular ED; ineffective in psychogenic ED | Headache, nasal congestion, visual disturbances | Works only if sexual ar