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Pick up to three peptides to see how their mechanisms, studied uses and evidence levels differ. Rows where the entries disagree are marked with a blue edge.
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Comparison
Melanotan II
Cosmetic & dermatologic
Evidence level
Limited evidence
Approval status
Not approved
Mechanism of action
- 1.Binds melanocortin receptors (MC1, MC3, MC4) rather than a single receptor, which explains its broad effects.
- 2.MC1 receptor activation in the skin stimulates melanocytes to produce darker pigment.
- 3.MC4 receptor activation in the brain affects appetite and sexual arousal pathways.
- 4.Because it is not selective, side effects across multiple systems are expected rather than incidental.
Studied for
- Sunless tanning and photoprotection (early phase I studies, abandoned)
- Male erectile dysfunction (small early trials, superseded by other drugs)
- Sexual arousal in women (small pilot studies)
- Appetite suppression (investigated, not developed)
Reported effects
- Visible skin darkening within days of use in early studies
- Increased sexual arousal reported in small trials
- Nausea, flushing and appetite loss in most participants
- Darkening of moles was noted, which complicates skin-cancer surveillance
Side effects
- Nausea and vomiting, common in trials
- Facial flushing and spontaneous erections
- Darkening of existing moles and new pigmented lesions
- Changes in blood pressure and heart rate reported
- Cases of severe skin reactions and systemic illness from unregulated products
Research protocol
Research context only — there is no approved protocol and no legitimate supply. Phase I studies used injected microgram doses with monitoring. Products sold online are unregulated, frequently mislabelled, and have been linked to serious adverse events.
Research context only
Evidence justification
Only small, old phase I and pilot studies exist. Development stopped, no regulatory approval was pursued, and post-market harm reports outweigh any published benefit data.