Cosmetic & Skin

Palmitoyl Tetrapeptide-7 is a signal peptide and fragment of immunoglobulin G that functions as a potent anti-inflammatory agent in cosmetic formulations. It effectively reduces interleukin-6 (IL-6) secretion in keratinocytes and inhibits UVB radiation-induced inflammatory responses, with studies demonstrating up to 86% reduction in interleukin production after UV exposure. The peptide also stimulates the production of laminin IV, laminin V, and collagen VII, making it one of the most widely used peptides in anti-aging cosmetics, particularly as a key component of Matrixyl 3000.

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.

Pentapeptide-18 is a synthetic neuropeptide (Tyr-D-Ala-Gly-Phe-Leu) that mimics the mechanism of enkephalins to reduce expression wrinkles. It works by modulating calcium channels in neurons to inhibit acetylcholine release, thereby reducing muscle contractions that cause wrinkles. Clinical studies demonstrate 11-34% wrinkle reduction with topical application, with enhanced efficacy when combined with other neuropeptides like Argireline. Pentapeptide-18 is considered a non-invasive, topical alternative to botulinum toxin injections.

Glutathione (GSH) is a tripeptide composed of glutamate, cysteine, and glycine that serves as the body's most abundant endogenous antioxidant and critical regulator of oxidative stress, redox homeostasis, and immune function. It functions through direct neutralization of free radicals and as a cofactor for antioxidant enzymes like glutathione peroxidase. Research applications span neurodegenerative diseases (Alzheimer's, Parkinson's), metabolic disorders (diabetes, NAFLD), respiratory conditions (COPD), immune function (COVID-19), exercise performance, and dermatological applications. Clinical trials demonstrate that oral supplementation (250-1000 mg daily) can increase tissue glutathione levels by 17-35% in blood compartments and up to 260% in buccal cells, with evidence showing improvements in oxidative stress markers, glycemic control in diabetics, liver function in NAFLD, and reduced muscle fatigue. Glutathione is not FDA-approved as a drug but is available as a dietary supplement; intravenous formulations lack FDA approval for cosmetic uses and carry safety concerns. The compound is widely researched with generally favorable safety profiles for oral and topical administration.

AHK-Cu is a synthetic copper peptide composed of three amino acids (alanine, histidine, and lysine) complexed with copper ions. Research demonstrates that AHK-Cu stimulates hair follicle growth by promoting dermal papilla cell proliferation and preventing apoptosis at concentrations of 10⁻¹² to 10⁻⁹ M. The peptide enhances VEGF production while reducing TGF-β1 secretion, supporting angiogenesis and tissue regeneration. Beyond hair growth, copper peptides show significant benefits for skin regeneration, wound healing, and anti-aging through enhanced collagen and elastin synthesis.

Palmitoyl Tripeptide-1 is a synthetic signal peptide consisting of the tripeptide GHK (glycyl-histidyl-lysine) with a palmitic acid group attached to enhance skin penetration. It is a collagen fragment derived from type I collagen that acts as a matrikine to stimulate extracellular matrix protein synthesis, particularly collagen, elastin, and glycosaminoglycans, by interacting with dermal fibroblasts. Clinical studies have demonstrated statistically significant improvements in skin thickness (4% increase), wrinkle reduction (23% decrease in depth), and skin roughness when applied topically at concentrations of 3-6 ppm over 4 weeks. The palmitoylation significantly increases lipophilicity and dermal stability compared to the native GHK peptide, making it more effective for cosmetic applications.

Alpha-melanocyte-stimulating hormone (α-MSH) is a 13-amino acid neuropeptide derived from proopiomelanocortin (POMC) that acts as a potent regulator of melanogenesis, immune function, and metabolic homeostasis. By binding to melanocortin receptors (primarily MC1R in melanocytes), α-MSH stimulates eumelanin synthesis, enhances DNA repair mechanisms, and provides photoprotection against UV-induced damage. Beyond pigmentation, α-MSH exhibits powerful anti-inflammatory properties by modulating cytokine production and immune cell function, regulates appetite and energy expenditure through central melanocortin pathways, and influences sexual arousal and erectile function via MC3R and MC4R activation in the hypothalamus.