Cosmetic & Skin

Melanotan 2 (MT-2) is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (α-MSH) with the molecular formula C50H69N15O9 and CAS number 121062-08-6. It functions as a non-selective agonist of melanocortin receptors MC1, MC3, MC4, and MC5, demonstrating up to 1000 times greater potency than endogenous α-MSH. Originally developed for photoprotection through melanogenesis, clinical research has primarily focused on its effects on sexual function, with multiple double-blind placebo-controlled trials demonstrating significant erectogenic properties in men with both psychogenic and organic erectile dysfunction. Additional research areas include metabolic effects, neuroprotection, and appetite suppression. Despite showing clinical efficacy in phase I trials, Melanotan 2 has never received regulatory approval from the FDA, EMA, TGA, or other major health authorities. It remains widely available through unregulated online markets as an unapproved cosmetic tanning agent and sexual enhancement compound, with significant safety concerns including associations with melanoma development, dysplastic nevi, nausea, cardiovascular effects, and unknown long-term risks due to lack of comprehensive safety studies.

GHK-Cu (glycyl-L-histidyl-L-lysine-copper) is a naturally occurring copper-binding tripeptide first isolated from human plasma in 1973. It functions as a signaling molecule that modulates multiple cellular pathways involved in tissue repair and regeneration. The peptide's concentration in human plasma declines from approximately 200 ng/mL at age 20 to 80 ng/mL by age 60, correlating with decreased regenerative capacity. GHK-Cu works through several mechanisms including copper ion transport, gene expression modulation (affecting over 4,000 human genes), collagen and elastin synthesis stimulation, antioxidant activity via superoxide dismutase enhancement, and growth factor pathway activation. Research demonstrates efficacy in wound healing, skin regeneration, hair follicle stimulation, and anti-inflammatory responses across multiple tissue types. The peptide is not FDA-approved for therapeutic use but is widely used in cosmetic products. It was recently added to FDA's Category 1 bulk substances list for 503A compounding, though not for injectable routes. GHK-Cu is available primarily through compounding pharmacies for research purposes and in topical cosmetic formulations marketed for anti-aging and skin rejuvenation applications.

Melanotan I (Afamelanotide) is a synthetic peptide analogue of α-melanocyte-stimulating hormone (α-MSH). It is FDA-approved under the brand name Scenesse for the treatment of erythropoietic protoporphyria (EPP), a rare genetic disorder causing severe photosensitivity. Unlike Melanotan II, Melanotan I is a linear peptide and has a different mechanism and safety profile.