Palmitoyl Tripeptide-8

Overview

The peptide corresponds to the C-terminal His-D-Phe-Arg portion of alpha-MSH, conjugated to palmitic acid to improve skin penetration. Alpha-MSH is a natural regulator of cutaneous inflammation, and its C-terminal tripeptide retains potent anti-inflammatory activity against cytokines such as IL-1, IL-6 and TNF-alpha.

In cosmetic evaluations summarised in a review of peptides for sensitive skin, palmitoyl tripeptide-8 binds the melanocortin-1 receptor (MC1R) with affinity comparable to alpha-MSH but only weak melanogenic (pigmenting) activity, allowing it to modulate the inflammatory response without darkening the skin. In vitro it inhibits UVB-induced IL-8 in keratinocytes and IL-1-stimulated IL-8 in fibroblasts, and in skin-explant models of neurogenic inflammation it reduces substance-P-driven vasodilation and oedema.

It is used topically, typically at low concentrations (on the order of a few parts per thousand of the active peptide solution), as a soothing active in serums and creams for reactive, easily flushed skin.

Mechanism of Action

By binding MC1R with alpha-MSH-like affinity but minimal melanogenic signalling, the peptide reproduces melanocortin anti-inflammatory tone without stimulating pigmentation. It lowers cytokine output from UVB-stressed keratinocytes and activated fibroblasts and, in neurogenic-inflammation models, blunts substance-P-induced capillary dilation, vessel-size increase and oedema, translating into a calming, anti-redness effect on reactive skin.