Palmitoyl Tetrapeptide-7

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.

Anti-Inflammatory Effects: Palmitoyl Tetrapeptide-7 demonstrates potent anti-inflammatory properties by suppressing pro-inflammatory cytokine production, specifically reducing interleukin-6 (IL-6) secretion in keratinocytes in both resting and UV-exposed states^[1][2][3]. In vitro studies show dose-dependent reduction in interleukin production up to 40%, with cells exposed to UV radiation and then treated achieving an 86% reduction of interleukin production^[4]. By downregulating IL-6 and IL-8 production, the peptide helps mitigate inflammation-related skin damage and aging, protecting the skin's foundational collagen and elastin structure from chronic inflammatory breakdown^[1][5].

Skin Rejuvenation and Wrinkle Reduction: Clinical studies demonstrate significant anti-aging effects with measurable improvements in skin parameters. A 4-week clinical trial showed 14.07% reduction in crow's feet wrinkles, 8.79% increase in skin elasticity, and 27.63% improvement in dermal density^[6]. A 12-week study revealed 28.12% increase in skin hydration, 18.81% improvement in elasticity, and 54.99% increase in collagen production^[7]. A cream containing 15 ppm of the peptide applied for one month showed remarkable increases in firmness (face: 19%, neck: 40%), elasticity (face: 17%, neck: 27%), and a 56% decrease in deepest wrinkles after just 15 days^[8].

Collagen and Extracellular Matrix Stimulation: As a signal peptide, Palmitoyl Tetrapeptide-7 stimulates fibroblast proliferation and promotes synthesis of key structural proteins^[7][9]. In vitro studies reveal the peptide significantly stimulates fibroblast proliferation and markedly promotes collagen and elastin synthesis, with elastin expression increasing approximately fivefold^[7]. The peptide specifically stimulates production of laminin IV, laminin V, and collagen VII, supporting dermal-epidermal junction integrity and skin repair processes^[2][3]. Laboratory studies of Matrixyl 3000 formulations show increases in glycosaminoglycans (287%), collagen I (117%), and collagen IV (327%)^[10].

UV Protection and Photoaging Prevention: The peptide specifically targets UV-induced damage by inhibiting the inflammatory cascade triggered by ultraviolet radiation exposure^[1][2][11]. By reducing inflammation after UVB exposure and suppressing IL-6 secretion—a key mediator of the sunburn reaction—Palmitoyl Tetrapeptide-7 helps prevent photoaging and maintain skin health under environmental stress^[11][12]. This UV-protective effect complements its anti-aging benefits by addressing both intrinsic and extrinsic aging pathways^[13].

Regulatory Safety Assessment: The Cosmetic Ingredient Review (CIR) Expert Panel conducted a comprehensive safety assessment and concluded that Palmitoyl Tetrapeptide-7 is safe in cosmetics at present practices of use and concentration, which are typically less than 10 ppm. The Panel noted that the low use concentrations and negative safety test data obviate any concerns relating to the safety of this ingredient in cosmetic products. This authoritative safety determination was published in the International Journal of Toxicology in 2018 and represents the most comprehensive independent safety evaluation available.

Clinical Safety Data: Clinical trials consistently demonstrate excellent safety profiles with no adverse reactions reported. In a human repeated insult patch test (HRIPT) involving 52 healthy subjects exposed to a mixture containing 500 ppm Palmitoyl Tetrapeptide-7, results did not indicate potential for dermal irritation or allergic contact sensitization. Multiple clinical studies, including a 12-week trial, reported no adverse reactions in participants such as skin papules, erythema, scabbing, or desquamation^[7]. A 4-week study with 20 female volunteers reported no adverse dermatological reactions during the trial period^[6]. No subjects in various clinical trials discontinued participation due to adverse events or allergic/irritant contact dermatitis^[7].

Ocular Safety: In the hen's egg chorioallantoic membrane (HET-CAM) in vitro assay, a mixture containing 500 ppm Palmitoyl Tetrapeptide-7 was classified as slightly irritating with a mean irritation index of 3.75, indicating minimal ocular irritation potential at cosmetic use concentrations.

Use in Sensitive Skin Products: Palmitoyl Tetrapeptide-7 has been identified as one of seven peptides commonly used in cosmetic products specifically formulated for sensitive skin from multinational brands^[2]. The peptide is biocompatible, biodegradable, and generally recognized as safe for topical application, with toxicity assessments conducted by both manufacturers and independent review committees supporting the FDA. However, most available safety information derives from patents and supplier brochures rather than extensive peer-reviewed clinical publications, representing a limitation in the evidence base^[2][8].