Palmitoyl Tripeptide-1

Palmitoyl tripeptide-1 (also called pal-GHK, and sold under names including palmitoyl oligopeptide) is the tripeptide Gly-His-Lys with a 16-carbon palmitic acid chain attached to the N-terminus. Its PubChem entry names it precisely: L-Lysine, N-(1-oxohexadecyl)glycyl-L-histidyl- (C30H54N6O5, MW 578.8, CAS 147732-56-7).

The palmitoyl group is the whole point, and understanding why explains most of modern cosmetic peptide design. GHK itself is a small hydrophilic peptide — exactly the kind of molecule the lipophilic stratum corneum is built to keep out. Attaching a fatty acid chain makes the conjugate far more lipophilic, so it partitions into the skin barrier instead of sitting on top of it. The lipid tail is a delivery device, not a second active ingredient.

This is why palmitoylated peptides dominate cosmetic formulation while their unmodified parents mostly do not, and it is the single most useful thing to understand when comparing products: 'palmitoyl' in an INCI name usually signals that the formulator addressed the permeability problem rather than ignoring it.

It is frequently combined with palmitoyl tetrapeptide-7 in commercial complexes, where the two are marketed together as a matrix-signalling pair.

The limiting factor for every topical peptide is delivery. Peptides are hydrophilic and relatively large, while the stratum corneum is a lipophilic barrier built to exclude exactly such molecules. A peptide that performs well in a fibroblast culture has not thereby been shown to reach fibroblasts through intact skin. Reviews of cosmeceutical peptides identify this permeability gap — not receptor pharmacology — as the principal open problem, and note that formulation strategies such as oil-in-water and water-in-oil-in-water emulsions are used to try to close it with uncertain success.

Independent, ingredient-isolated clinical evidence is thin; most product claims rest on multi-ingredient formulations where this peptide's specific contribution cannot be separated out. Improved lipophilicity increases partitioning into the stratum corneum but does not by itself prove that an intact, active peptide reaches viable dermis at meaningful concentration.

Palmitoyl tripeptide-1 is C30H54N6O5, MW 578.8, CAS 147732-56-7, PubChem CID 10231864. The C16 palmitoyl chain roughly doubles the molecular weight relative to free GHK while substantially increasing lipophilicity — the trade-off that makes topical delivery plausible.