Overview
Melanotan II is a synthetic analog of alpha-melanocyte stimulating hormone (α-MSH) that stimulates melanogenesis (skin tanning) and has secondary effects on sexual arousal and appetite suppression. It was originally developed at the University of Arizona as a potential sunless tanning agent to reduce skin cancer risk. It is one of the most widely used cosmetic peptides despite lacking regulatory approval.
Mechanism of action
Melanotan II binds non-selectively to melanocortin receptors MC1R through MC5R. MC1R activation stimulates melanocytes to produce eumelanin (dark pigment), producing a tan without UV exposure. MC4R activation affects sexual arousal (which led to the development of PT-141). MC3R/MC4R activation suppresses appetite. The broad receptor binding profile explains the diverse effects and side effect profile.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| tanning | subcutaneous | 250–500 mcg | daily | Loading phase: 250-500mcg daily for 2-3 weeks. Maintenance: 250mcg 1-2x/week. Start low to assess nausea tolerance. |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
University of Arizona studies demonstrated significant increases in skin pigmentation in fair-skinned individuals with reduced UV exposure requirements. Phase II trials showed tanning effects within 5-7 days. Sexual arousal effects in both men and women were a consistent finding. Side effects include nausea (especially initial doses), facial flushing, fatigue, and potential for new or changed moles. Long-term safety data is limited.
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with Melanotan II for synergistic effects.
Legal status
Not FDA-approved. Sold as a research peptide. Regulatory agencies (FDA, TGA, MHRA) have issued warnings against its cosmetic use. Not scheduled or banned in most jurisdictions.
Where to get it
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