Palmitoyl Pentapeptide-4

Palmitoyl Pentapeptide-4, marketed under the trade name Matrixyl by the French cosmetic ingredient manufacturer Sederma SAS since its launch in 2000, is a synthetic lipopeptide consisting of the five-amino-acid sequence Lysine-Threonine-Threonine-Lysine-Serine (KTTKS) conjugated to a 16-carbon palmitic acid chain (Pal-KTTKS). Its molecular formula is C39H75N7O10, with a molecular weight of approximately 802 g/mol, PubChem CID 9897237, and CAS number 214047-00-4.

At Verified Peptides, we classify Palmitoyl Pentapeptide-4 as a matrikine — a class of bioactive peptide fragments derived from extracellular matrix proteins that function as cell-signaling molecules. The KTTKS sequence itself is a naturally occurring fragment of the C-terminal propeptide of human procollagen type I, the precursor molecule from which mature collagen is formed. The palmitic acid conjugation is not incidental to its research design: the added fatty-acid chain substantially increases the lipophilicity of the otherwise water-soluble pentapeptide, improving its ability to penetrate the outer skin barrier (stratum corneum) for topical research applications, a common design strategy for peptides intended to reach dermal fibroblasts from the skin surface.

Unlike most compounds in this build batch, Palmitoyl Pentapeptide-4's primary research and commercial history is as a topical cosmetic-science ingredient rather than a systemically administered investigational drug candidate, and its regulatory pathway reflects that distinction.

Palmitoyl Pentapeptide-4 is frequently discussed alongside a broader family of “signal peptide” ingredients that emerged in cosmetic chemistry following its commercial success, several of which use a similar design logic of pairing a short bioactive amino acid sequence with a lipid chain for skin penetration. Researchers new to this ingredient class should note that not every peptide marketed with a similar naming convention shares Palmitoyl Pentapeptide-4's specific KTTKS sequence or its particular matrikine mechanism, even when marketed under closely related brand names.

At Verified Peptides, we point researchers to Palmitoyl Pentapeptide-4's foundational clinical trial (Robinson LR, Fitzgerald NC, Doughty DG, et al., International Journal of Cosmetic Science, 2005, 27(3):155–160; PMID 18492182) as the primary published evidence for its topical efficacy. This 12-week, double-blind, placebo-controlled, split-face study enrolled 93 Caucasian female subjects aged 35–55, comparing a moisturizer base against the same moisturizer formulated with 3 parts-per-million pal-KTTKS. The treated side showed statistically significant improvement in wrinkles and fine lines relative to placebo, assessed by both quantitative image analysis and expert visual grading, and the compound was reported as well tolerated throughout the study.

A more recent randomized, double-blind trial (Journal of Clinical and Aesthetic Dermatology, 2023; PMID 36909866) directly compared Palmitoyl Pentapeptide-4 cream against Acetylhexapeptide-3 (Argireline) cream and placebo for crow's-feet wrinkles over 8 weeks in a small cohort. Palmitoyl Pentapeptide-4 showed numerically better results than both comparators on clinical assessment and patient-satisfaction measures, but the trial did not reach statistical significance, a limitation the study authors attributed directly to its small sample size. We are reporting this honestly as a directionally favorable but statistically inconclusive result rather than rounding it up to a confirmed finding.

Beyond these two peer-reviewed trials, secondary sources describe a broader body of industry and academic research reporting roughly 10–30% wrinkle-depth reduction versus baseline across various published studies of palmitoylated pentapeptide formulations, though we have not independently confirmed a single systematic review meeting this description with a verifiable PMID, and are noting this as a general research-literature characterization rather than citing it as a specific paper.

Because Palmitoyl Pentapeptide-4 is formulated and marketed as a cosmetic ingredient rather than pursued through a pharmaceutical drug-approval pathway, its regulatory history differs meaningfully from the injectable, systemically administered peptides elsewhere in our catalog: it has been reviewed by the Cosmetic Ingredient Review (CIR) panel, an independent scientific body that assesses cosmetic ingredient safety in the United States, rather than by the FDA's drug-approval process, since it has never been developed or marketed as a drug.

Palmitoyl Pentapeptide-4 was one of the first matrikine-based peptides to reach wide commercial use in skincare, and its 2000 launch under the Matrixyl brand name predates most of the other signaling and carrier peptides now common in cosmetic chemistry. Its underlying scientific rationale — using a natural collagen-breakdown fragment to trick fibroblasts into a repair response — was itself built on academic research into how the body senses matrix damage, rather than being an arbitrary formulation choice.

A frequently confused point is the distinction between “signaling peptides” like Palmitoyl Pentapeptide-4, which are believed to trigger a specific fibroblast response by mimicking a natural biological signal, and “carrier peptides” such as copper tripeptide (GHK-Cu), which are believed to work partly by transporting a cofactor (copper) into tissue to support enzymatic processes. Both classes are studied for skin-matrix effects, but through mechanistically distinct routes, and combining them is a common research and formulation strategy precisely because they are not expected to compete for the same pathway.

Sederma has also developed a related compound, Palmitoyl Tripeptide-1 (marketed as Matrixyl 3000 in combination with Palmitoyl Tetrapeptide-7), which is a separate, shorter sequence rather than a newer version of Palmitoyl Pentapeptide-4 itself — a distinction worth noting given how similarly the various “Matrixyl” branded products are often marketed to consumers despite containing different active peptides.

Because Palmitoyl Pentapeptide-4 was developed and commercialized specifically for topical cosmetic use rather than systemic administration, the bulk of its published research uses topical application models (cell culture, ex vivo skin explants, and human split-face trials) rather than the injectable-route pharmacokinetic studies more typical of the systemically administered peptides in this catalog.

At Verified Peptides, we require third-party HPLC purity testing and mass spectrometry identity confirmation for every batch of research-grade Palmitoyl Pentapeptide-4 we offer, with a Certificate of Analysis (COA) available for each lot. Because this compound includes a fatty-acid conjugation in addition to its peptide backbone, both the amino acid sequence and the completeness of the palmitoylation reaction are relevant quality parameters, and a poorly conjugated batch may behave meaningfully differently in penetration-focused research than a properly conjugated one.

We source exclusively from manufacturers operating under Good Manufacturing Practice (GMP)-aligned quality systems, and every lot is independently verified rather than accepted solely on a supplier's internal documentation. Researchers should request and review the specific COA for their lot, checking purity percentage and confirmed molecular identity, rather than assuming consistent quality across suppliers or even across different lots from the same source.

Given that Palmitoyl Pentapeptide-4 is most commonly studied in topical and dermal research contexts, formulation-stage considerations — solubility, vehicle compatibility, and stability once incorporated into a topical preparation — are an additional layer of quality control relevant to this specific compound that does not apply in the same way to injectable research peptides.

Lyophilized (freeze-dried) Palmitoyl Pentapeptide-4 is stable when stored at -20°C, protected from light and moisture, and can generally be expected to retain integrity over extended periods in this unreconstituted form.

Once reconstituted or incorporated into a research formulation, Palmitoyl Pentapeptide-4 should be stored according to the specific formulation's documented stability guidance, since its behavior in solution can vary depending on the vehicle or carrier used. Researchers working with the raw material in solution (rather than as a finished topical formulation) should store reconstituted solutions refrigerated at 2–8°C, use them within the documented timeframe, and avoid repeated freeze-thaw cycling, which can degrade peptide integrity over time.

As with other peptides in this catalog, extended exposure to heat, direct light, or room-temperature storage will accelerate degradation of both the peptide backbone and the fatty-acid conjugation, potentially altering the compound's skin-penetration properties as well as its raw structural integrity. Following the lot-specific storage documentation provided with each order is the most reliable way to preserve research validity.