Palmitoyl tripeptide-5 is a cell signalling cosmeceutical (see the list here) that could speed up collagen synthesis in skin.
“Peptides are another group of novel ingredients included in the line treatment that play an important role in collagen synthesis and degradation. These protein building blocks are used in the body to signal between cells and influence the up- and down-regulation of various cellular functions. One of the peptides included in the treatment, palmitoyl tripeptide-5, is a synthetic peptide that mimics the sequence found in the protein thrombospondin 1 (TSP-1). TSP-1 has been shown to activate latent tissue growth factor β (TGF-β), a growth factor involved in the stimulation of collagen production.” (This study.)
From this post: I found it at Lotioncrafter as Syn®-Coll (INCI: Palmitoyl Tripeptide-5, Glycerine) which is used at 1% to 3% in the aqueous phase – it can handle heat up to 80˚C so you can use it in the heated phase – to stimulate collagen synthesis and increase skin firming while moisturizing. It may reduce the appearance of wrinkles and stretch marks. Water soluble.
Found as part of SYN-Coll, Eye Complex 4, or LCPeptide Syn-6 (Lotioncrafter), to name a few.