Palmitoyl pentapeptide-4: evidence, FDA status and research

It is put in anti-wrinkle creams, often under the name Matrixyl, to smooth fine lines. One trial of 93 women showed a small gain, but the maker ran it and no one else has repeated it.

Sold for

Palmitoyl pentapeptide-4, better known as Matrixyl, is the peptide most anti-wrinkle creams point to when they say peptides work.

Studies say

A single sponsor-run randomized trial found modest wrinkle improvement versus the same moisturizer without the peptide, which is better evidence than most cosmetic peptides have and still short of independent confirmation.

Why grade B. One randomized, double-blind, placebo-controlled split-face trial in 93 women showed a measurable reduction in fine lines and wrinkles over 12 weeks, backed by a 1993 cell study identifying the five-amino-acid sequence as a stimulator of collagen production. The trial was run by the manufacturer and has not been independently replicated, which caps it at B. ¹²

FDA. Palmitoyl pentapeptide-4 is a cosmetic ingredient, sold under trade names such as Matrixyl. It is not approved by the FDA as a drug for any use; the FDA regulates cosmetics but does not approve their ingredients. ³⁴

Written from 5 cited sources. Last refreshed 2026-10-27. Not physician reviewed.

What this means for you

What people take it for: Smoothing fine lines and wrinkles
Can a US doctor prescribe it?: No prescription; it is a cosmetic ingredient.
Properly tested in people?: Partly: one 12-week trial of 93 women, run by the maker and never repeated.

Evidence checklist

Randomised controlled trial Double-blind split-face trialyes
Human study over 100 people 93 women, 12 weeksno
More than one research group Manufacturer trial, not replicatedno
Clinical outcomes, not surrogate markers Wrinkle appearance, not health outcomesno
Human safety data beyond case reports Tolerated in one 12-week trial onlyno

Drawn from the cited studies below. A dash means the sources give no information.

What it is

Palmitoyl pentapeptide-4 is the five-amino-acid sequence lysine-threonine-threonine-lysine-serine, taken from the end of the type I collagen precursor, with a palmitic acid tail added so it can pass through the skin's oily surface. The sequence was identified in 1993 as the smallest fragment of the collagen propeptide that still stimulated matrix production in cultured cells. ²

Sederma commercialized it as Matrixyl in 2000, and it is now one of the most common peptides in anti-aging products, from drugstore creams to premium serums. It is sold as a cosmetic ingredient, listed on labels under its INCI name. ³⁴

How it works

When collagen is made, the cell trims propeptides off each end of the molecule. Those trimmed fragments act as feedback signals. The 1993 study showed that one such fragment, and specifically the KTTKS pentapeptide within it, told fibroblasts to make more type I and III collagen and fibronectin without changing total protein synthesis. The cosmetic premise is that applying this signal from outside nudges aging skin to rebuild its matrix. The palmitoyl tail is there to get the peptide through the stratum corneum. ¹²

What human research shows

The main trial enrolled 93 women aged 35 to 55 with photoaged skin. Each applied a moisturizer with the peptide to one side of the face and the same moisturizer without it to the other, assigned at random and blinded, for 12 weeks. Both quantitative image analysis and expert graders found significantly greater reduction in fine lines and wrinkles on the peptide side. The effect size was modest, consistent with a cosmetic result, not a procedural one. ¹

The study was conducted by Procter and Gamble researchers, the trial duration was short, and no independent group has published a replication. Later studies of Matrixyl have mostly tested it inside multi-ingredient products or in combination with other peptides, which does not isolate its effect. ¹³

Study	Model	Finding
Robinson 2005 split-face trial	Humans, n=93 women, randomized double-blind placebo-controlled split-face, 12 weeks	Moisturizer with palmitoyl pentapeptide-4 reduced fine lines and wrinkles significantly more than the same moisturizer without it. ¹
Katayama 1993 pentapeptide discovery	Cultured human fibroblasts and other mesenchymal cells	The KTTKS pentapeptide from the collagen propeptide was the minimum sequence that stimulated collagen and fibronectin production. ²

Safety

The peptide was well tolerated in the 12-week trial, with no difference in irritation between the treated and placebo sides. It is used at very low concentrations in finished products. As with any topical ingredient, contact allergy is possible but has not been specifically reported. The FDA does not review cosmetic ingredients before sale, so post-market reports are the main safety signal. ¹⁴

Questions for your clinician

Has anyone other than the maker repeated the wrinkle trial?
How does it compare with retinoids or sunscreen for my skin goals?
How do I test for irritation before regular use?

Questions people ask

Is Matrixyl the same as palmitoyl pentapeptide-4?

Matrixyl is Sederma's trade name for an ingredient whose active is palmitoyl pentapeptide-4. Newer products called Matrixyl 3000 and Matrixyl Synthe'6 contain different peptides, so the name alone does not tell you which one is in a product. ³

How well does it work?

In the one controlled trial, the improvement in wrinkles was statistically significant but modest, and visible mainly on close measurement. It is a cosmetic effect over 12 weeks, not a substitute for retinoids or procedures. ¹

Can it replace retinol?

There is no head-to-head trial. Retinoids have far more clinical data, including long-term studies and prescription approvals. Palmitoyl pentapeptide-4 has one sponsor-run trial and is often marketed as a gentler alternative for people who do not tolerate retinoids. ¹⁴

Does the FDA approve it?

No, and it does not need to be. It is sold as a cosmetic ingredient, which the FDA regulates for safety and labeling but does not approve in advance. If a product claimed to treat a skin disease it would be classified as a drug and would need approval. ⁴⁵

Citations

Robinson 2005, Int J Cosmet Sci: topical palmitoyl pentapeptide provides improvement in photoaged human facial skin doi.org
Katayama 1993, J Biol Chem: a pentapeptide from type I procollagen promotes extracellular matrix production pubmed.ncbi.nlm.nih.gov
SpecialChem: palmitoyl pentapeptide-4 INCI ingredient entry specialchem.com
FDA: how cosmetics are not FDA-approved but are FDA-regulated fda.gov
FDA: is it a cosmetic, a drug, or both? fda.gov