Palmitoyl Tetrapeptide-7

Palmitoyl Tetrapeptide-7 (INCI: palmitoyl tetrapeptide-7; peptide sequence: Gly-Gln-Pro-Arg, N-terminally palmitoylated) is a lipopeptide developed by Sederma (France) as a skin-targeted anti-inflammatory and anti-ageing signal peptide. It is one of the key components in the Matrixyl 3000 complex, where it is formulated alongside Palmitoyl Tripeptide-1 (Pal-GHK).

The peptide operates through a mechanism distinct from pure collagen-stimulating peptides: it suppresses inflammatory cytokine production in keratinocytes and dermal fibroblasts. Specifically, Palmitoyl Tetrapeptide-7 reduces production of IL-6 (interleukin-6) and IL-8 (interleukin-8), two cytokines that are chronically elevated in photoaged, UV-damaged, and environmentally stressed skin. This chronic low-grade inflammation - sometimes called "inflammageing" - is now recognised as a major contributor to accelerated skin ageing, collagen degradation, and impaired barrier function.

By dampening this inflammatory signalling, Palmitoyl Tetrapeptide-7 addresses a root cause of photoageing rather than simply stimulating new collagen production. When combined with collagen-stimulating peptides like Matrixyl (which works via the TGF-beta and messenger peptide pathways to upregulate collagen synthesis), the result is a dual approach: reduce the inflammatory damage driving collagen breakdown while simultaneously stimulating new collagen production.

The palmitoyl (C16 fatty acid) modification at the N-terminus is the standard approach for improving the skin penetration of hydrophilic peptides. Peptides alone are poorly absorbed through the stratum corneum; the lipophilic palmitoyl chain increases affinity for the lipid-rich stratum corneum, improving penetration to the viable epidermis and dermis where the target cells reside.

Research into Palmitoyl Tetrapeptide-7 has also documented effects on hyaluronic acid synthesis - the naturally occurring polysaccharide responsible for skin hydration and volume. Hyaluronic acid production declines with age and UV exposure, contributing to skin thinning and dehydration. The combined stimulation of HA synthesis, collagen production, and IL-6/IL-8 suppression makes Palmitoyl Tetrapeptide-7 a genuinely multi-mechanism anti-ageing peptide.