Melanotan II
Non-selective melanocortin agonist studied for UV-less tanning and erectile function.
๐ฌ Mechanism of Action
Melanotan II (MT-2) is a synthetic analog of alpha-melanocyte-stimulating hormone (ฮฑ-MSH) that activates multiple melanocortin receptors. MC1R activation stimulates melanocytes to produce melanin, resulting in skin darkening (tanning) without UV exposure. MC3R/MC4R activation produces sexual arousal effects (the pathway that led to PT-141 development) and appetite suppression.
MT-2 is a non-selective melanocortin agonist, which means it produces multiple effects simultaneously: tanning, sexual function enhancement, and modest appetite reduction. The tanning effect is cumulative and persists for weeks to months after discontinuation.
Source: PMID: 10221658
๐Background & History
Melanotan II (MT-2) was developed at the University of Arizona in the 1980sโ90s by Mac Hadley and colleagues seeking a method to induce melanogenesis without UV exposure for skin cancer prevention. It is a cyclic analog of alpha-MSH with 1000ร greater potency than natural ฮฑ-MSH at MC1R. Serendipitously, researchers discovered its potent sexual arousal and appetite suppression effects via MC4R activation. It has never received regulatory approval and is considered a research compound.
๐ฏ Research Use Cases
- โTanning/melanogenesis without UV radiation
- โErectile dysfunction and sexual arousal (via MC4R)
- โAppetite suppression for weight management
๐ Dosing Protocol
| Typical Dose | 250-500 mcg/day (loading) |
| Frequency | Daily (loading 2 weeks), then 1-2ร/week maintenance |
| Half-Life | ~1 hour |
| Common Vial Sizes | 10 mg |
๐งช Reconstitution Example
โ ๏ธSafety & Considerations
Research peptide โ not FDA-approved. Common side effects include nausea (especially during loading phase), facial flushing, and potential changes to moles and freckles. Users should monitor existing moles for changes. May cause spontaneous erections in males.
โกInteractions & Contraindications
MC1R activation causes mole darkening and new nevus formation โ regular dermatological monitoring essential. Nausea common especially at higher doses. Spontaneous erections in men at standard doses. Do not use with cardiovascular disease. Use cautiously in patients with history of melanoma โ theoretical risk of activating dormant melanocytes.
๐Synergies & Common Stacks
PT-141 is a more selective MC4R agonist derived from MT-2 with reduced melanogenic side effects โ often preferred over MT-2 for pure sexual function goals.
