Palmitoyl Pentapeptide-4 (Matrixyl) bulk powder for formulators

Palmitoyl Pentapeptide-4 is the pentapeptide Lys-Thr-Thr-Lys-Ser carrying a palmitoyl group on its N-terminal lysine, written pal-KTTKS and known to most buyers by the originator's trade name Matrixyl. The sixteen-carbon fatty acyl tail makes the dry powder reluctant to dissolve in water and turns it into a surface-active molecule. Serum, emulsion and eye-cream formulators buy it, and their first question is usually how to get it into a base without haze.

Pepti, Guangzhou produces the material and supplies it as bulk powder from 5 g with cold-chain shipping, a lot COA giving HPLC purity and mass-spectrometry identity, and an SDS on request. No public batch record exists for this compound in the Pepti COA library yet, so the lot COA that travels with the shipment is the purity document.

Identity and naming: Pentapeptide-4, Pentapeptide-3 and the trade name

The INCI name changed once, and both versions are still in circulation.

• Palmitoyl Pentapeptide-4 is the current INCI name. PubChem CID 9897237 lists it with CAS 214047-00-4, formula C39H75N7O10 and a molecular weight of 802.1 g/mol, and carries both Palmitoyl Pentapeptide-3 and Matrixyl as synonyms.
• Palmitoyl Pentapeptide-3 is the former INCI name for the same molecule. Older formulations and some supplier catalogues still use it; a label written today should read Pentapeptide-4.
• Matrixyl is the originator's trade name. Pepti material is a generic equivalent sold under the INCI name and is not the originator's product.

The palmitic acid is amide-linked to the alpha-amine of the first lysine, and the C-terminal serine carries a free carboxyl. With two cationic lysine side chains and one anionic carboxyl at skincare pH, the molecule is a zwitterionic surfactant rather than a simple peptide.

Appearance, solubility and handling

The powder is white. As a dry solid it does not disperse cleanly in plain water: it floats, clumps or forms a cloudy suspension, because the palmitoyl chain dominates its behaviour. This is a property of the molecule, not a defect of the lot.

In practice the powder is dissolved first in a small volume of a glycol, such as butylene glycol or propanediol, or in a glycol-surfactant premix with a polysorbate or a PEG-free solubiliser, and the clear premix is added to the batch. In an emulsion it can instead go in through the oil phase or at the emulsification step.

The powder is hygroscopic; weigh it quickly from a container at room temperature. Pepti ships for storage at 2–8 °C protected from light, with −20 °C for long-term holding.

What the published literature reports

Two papers underpin most of what is written about this peptide, and a third, on its physical chemistry, is the most useful for a formulator.

Katayama and co-workers identified Lys-Thr-Thr-Lys-Ser, residues 212 to 216 of the carboxyl-terminal propeptide of type I procollagen, as the shortest sequence that stimulated collagen and fibronectin production in cultured fibroblasts and other mesenchymal cells (Katayama K et al. J Biol Chem, 1993).

Robinson and colleagues report a 12-week, double-blind, placebo-controlled split-face study in 93 female volunteers comparing a moisturiser with the same moisturiser containing pal-KTTKS at 3 ppm, and report fewer fine lines and wrinkles on the test side than on the control by image analysis and expert grading (Robinson LR et al. Int J Cosmet Sci, 2005).

In a preformulation study Mortazavi and colleagues compared KTTKS with its palmitoyl derivative and report that the free pentapeptide was freely water-soluble with a logP of about −1.6, while pal-KTTKS had a calculated logP of about 3.7, showed surface activity with a critical micelle concentration near 0.024 mM and decomposed near 150 °C without melting (Mortazavi SM et al. J Cosmet Sci, 2019).

These are the authors' findings in their own test systems, not a claim for a finished product.

Formulation notes for the bench

These notes are about getting the molecule into a base and keeping it intact.

• Solubiliser first. Decide the carrier before the first bench batch: a glycol premix, a solubiliser in the water phase, or the oil phase of an emulsion. Stirring the dry powder into a finished serum does not work.
• Order of addition. Make the clear premix, add it in the cool-down phase below 40 °C, and check clarity after the pH has been set. If a serum hazes, raise the solubiliser ratio inside the premix.
• pH window and heat. Hold the finished product between pH 4.5 and 7, where the peptide bonds and the palmitoyl amide are stable. Strongly acidic bases hydrolyse amide bonds slowly over the shelf life, and the loss shows on HPLC as a growing free-KTTKS signal. Brief exposure at emulsification temperature is routine; a long hold in hot oil is not.
• Charge. The two lysines are cationic at skincare pH, so anionic polymers such as carbomer can bind the peptide and alter viscosity or clarity; test the thickener combination early.
• Preservation. Confirm the preservative by challenge test in the buyer's own base.

The formulator sets the use level from stability work in their own base; Pepti publishes no recommendation.

Specification and documents for this material

The lot COA reports reverse-phase HPLC purity as area percent, mass-spectrometry identity against the expected 802.1 g/mol, appearance, and the storage and retest statements. Water content and counter-ion are included where the buyer's specification asks for them, and an SDS is available on request.

There is no public batch record for Palmitoyl Pentapeptide-4 in the Pepti COA library yet, which is why this page shows no record table. Your lot COA arrives with the shipment and states the purity of what you received; as a reference point, the public records Pepti publishes for other compounds currently sit between 98.4% and 99.8% HPLC purity.

Public batch records

No public batch record is listed for this compound in the manufacturer's library yet. The lot you receive carries its own COA with HPLC purity, MS identity and lot number; ask for the current lot's COA with your quote. The library itself is at peptioem.com/coa.