Melanotan I/II
Synthetic analogs of alpha-melanocyte-stimulating hormone (α-MSH), studied for melanocortin-receptor signaling and pigmentation research.
Overview
Melanotan I and II are synthetic analogs of alpha-melanocyte-stimulating hormone, a naturally occurring peptide hormone that regulates melanin production in skin cells. They were developed by researchers at the University of Arizona in the 1990s while investigating melanocortin-receptor pathways, originally in the context of skin-cancer and sun-protection research. Melanotan II is a smaller, cyclized version of Melanotan I with broader melanocortin-receptor activity.
Mechanism of Action
Both compounds act as agonists at melanocortin receptors, primarily MC1R, which stimulates melanocytes to produce more melanin (eumelanin), the pigment responsible for skin darkening. Melanotan II additionally interacts with other melanocortin receptor subtypes (including MC3R and MC4R), which is why it has also been studied for effects beyond pigmentation, such as appetite and sexual-response pathways in animal models.
Cited Research
Melanocortin receptor pharmacology
Foundational research characterizing MC1R agonism and its role in melanogenesis.
Photoprotection research
Studied for UV-protective pigmentation effects as an alternative to sun exposure in skin-cancer risk research.
MC3R/MC4R signaling
Melanotan II’s non-selective receptor activity has been studied in relation to appetite and other melanocortin-mediated pathways.
This is a summary, not an exhaustive review. Search the primary literature yourself: Melanotan on PubMed →
Safety & Handling
Melanotan I/II should be handled only by qualified personnel in a laboratory setting, stored and reconstituted per the Certificate of Analysis, and kept refrigerated once reconstituted. It is not evaluated or approved by the FDA for any human or veterinary use.
Frequently Asked Questions
What’s the difference between Melanotan I and II?
Melanotan I is the linear, more selective MC1R-focused analog studied first. Melanotan II is a smaller cyclic peptide with broader melanocortin-receptor activity, which is why it’s been studied for effects beyond pigmentation.
Is Melanotan legal to purchase?
It’s legal to sell and purchase as a research chemical for laboratory use in the U.S. It is not approved by the FDA as a drug or cosmetic ingredient for human use.
How should it be stored?
Keep the lyophilized powder refrigerated or frozen prior to reconstitution. Once reconstituted, keep refrigerated and use within the timeframe on its Certificate of Analysis.
Is this page medical advice?
No. This page summarizes published literature for research and educational context only. It does not recommend a dose, protocol, or use in humans or animals outside a laboratory setting.
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