Peptide Reference Desk
Palmitoyl Tetrapeptide-7 vs Palmitoyl Tripeptide-38: INCI identity before Matrixyl claims
Two palmitoylated cosmetic peptides with different sequences and branded ingredient histories should not share one efficacy or analytical record.
The trade-name shortcut causes the confusion
Palmitoyl Tetrapeptide-7 is commonly encountered as one component of Matrixyl 3000, paired with Palmitoyl Tripeptide-1. Palmitoyl Tripeptide-38 is associated with Matrixyl Synthe’6. They are different lipidated peptides, not revisions of the same INCI name.
Structure drives the analytical plan
Palmitoylation improves hydrophobic character but complicates solubility, recovery and chromatography. Method development should demonstrate that the stated mobile phase, column and sample diluent recover the declared peptide without adsorption or precipitation.
| Item | Professional record |
|---|---|
| Identity | Exact INCI, sequence, palmitoylation site and observed mass |
| Raw material | Neat peptide versus supplier solution or blend |
| Content | Active peptide basis, not trade-material percentage |
| Evidence | Isolated peptide, branded blend or finished formulation tested |
Why finished-product claims do not travel
A clinical cosmetic study can only support the tested formulation, concentration, packaging and use conditions. It cannot establish that any serum listing the same INCI will behave identically. Likewise, supplier data on a two-peptide mixture cannot be assigned to one component without component-specific evidence.
Stability belongs in the article
Formulators should consider pH, surfactants, preservatives, oxidation, container interaction and compatibility with other actives. A certificate at raw-material release says little about peptide integrity after months in a complex cosmetic formula.
Verify with primary records
Use the primary paper, current regulator label or lot-linked analytical file for the claim it supports. A search result is a route to evidence, not the evidence itself.