Peptides · Evidence-graded entry

Matrixyl (palmitoyl pentapeptide-4, pal-KTTKS): what the evidence shows

Name: Matrixyl (palmitoyl pentapeptide-4, pal-KTTKS): what the evidence shows
Creator: SoftMaxx AI Editorial
Published: 2026-09-30

Matrixyl (palmitoyl pentapeptide-4), evidence-graded: the best support is randomized human trials. Citations checked against PubMed and regulator records.

Written by SoftMaxx AI editorial · Citations checked against PubMed records · Updated 2026-10-01 · Not medically reviewed · How we grade evidence

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The verdict · strongest evidence Human RCT

Human RCT The best evidence is one randomized, double-blind split-face trial: 93 women used a moisturizer containing palmitoyl pentapeptide (pal-KTTKS) at the trial concentration (see the doses table) on one side of the face and the same moisturizer without it on the other for 12 weeks, and fine lines and wrinkles improved significantly more on the peptide side. A smaller 21-person, 8-week randomized trial found a palmitoyl pentapeptide-4 cream did better than an acetylhexapeptide-3 cream and placebo.^[1][2]

What Matrixyl is

Pal-KTTKS, the palmitoyl pentapeptide sold as Matrixyl (see Names on this page), is a five-amino-acid peptide (Lys-Thr-Thr-Lys-Ser, KTTKS) with a fatty-acid (palmitoyl) tail, used in anti-wrinkle creams ^[1]^[3]. The KTTKS sequence comes from type I procollagen, the collagen precursor ^[4], and pal-KTTKS was designed as a topical agent to stimulate collagen production ^[1]. A 2011 review notes relatively few clinical studies of it ^[3].

The palmitic-acid tail makes it more stable than plain KTTKS and lets more of it into the skin, at least in mouse skin tests ^[5].

In vitro (cells) In fibroblast cultures the KTTKS fragment is the minimal sequence that stimulates type I and III collagen and fibronectin production. Palmitoylation makes it more stable and lets measurable amounts reach the epidermis and dermis in mouse skin, whereas unmodified KTTKS did not penetrate.^[4][5][3]

Claims vs. evidence

Each popular claim, graded by the strongest study behind it. The words in quotation marks are how the claim is marketed; the text after the grade is what the studies show.

Claim as marketedReduces fine lines and wrinklesHuman RCT A positive 12-week split-face randomized trial (n=93) and a small 8-week three-arm randomized trial (n=21) in which a palmitoyl pentapeptide-4 cream did better than an acetylhexapeptide-3 cream and placebo. Neither abstract reports how large the improvement was.^[1][2]
Claim as marketedBoosts collagen productionIn vitro (cells) Collagen stimulation was measured in cultured fibroblasts. The two human trials measured wrinkles (image analysis, expert grading, photos) and, in the smaller one, skin hydration and elasticity; neither abstract reports a collagen measurement.^[4][1][2]
Claim as marketedGeneral topical peptide anti-aging benefitExpert review A 2026 meta-analysis of 19 randomized trials of oral and topical peptides found a modest pooled wrinkle effect, largely driven by oral polypeptides. Effects on elasticity and density were inconsistent.^[6]

Common myths, checked

Common beliefMatrixyl is proven to rebuild collagen in your face.In vitro (cells) Collagen stimulation was shown in cell culture. The 93-person trial measured wrinkles and fine lines by image analysis and expert grading; its abstract reports no collagen measurement.^[4][1]
Common beliefMatrixyl is a copper peptide.Expert review It contains no copper: pal-KTTKS is a palmitoyl pentapeptide ^[1] whose KTTKS sequence comes from type I procollagen ^[4].^[3][4][1]
Common beliefMatrixyl works as well as tretinoin.No supporting study We found no head-to-head trial of Matrixyl against tretinoin. The two trials we found compared a moisturizer with palmitoyl pentapeptide (pal-KTTKS) against the same moisturizer without it, and a palmitoyl pentapeptide-4 cream against an acetylhexapeptide-3 cream and placebo.^[1][2]

Doses used in studies (not a recommendation)

These are the amounts given to the people, animals or cells in the cited studies, copied as reported. They are a record of what was tested, not dosing instructions, and nothing here says what you should take.

Studied in	Route	Amount reported	How often	How long	n	Source
Humans	topical moisturizer, split-face	3 ppm pal-KTTKS in a moisturizer (the trial concentration)	not stated in abstract	12 weeks	93	^[1] 93 Caucasian women aged 35–55 with photoaged skin; double-blind, placebo-controlled, split-face
Humans	topical cream to periorbital area	not stated in abstract	twice daily	8 weeks	21	^[2] 21 Indonesian women aged 26–55 (3 arms)

Side effects and risks

Human RCT Well tolerated by the skin in the 93-person, 12-week trial^[1]

Regulatory status (checked 2026-09-30)

United States (FDA)We found no FDA-approved product containing palmitoyl pentapeptide-4 in Drugs@FDA (searched 2026-10-01). (FDA: Drugs@FDA search: matrixyl — no approved product found) FDA does not approve cosmetic products or ingredients (other than color additives) before they go on the market, and a product intended to affect the structure or any function of the body is legally a drug. (FDA: Is It a Cosmetic, a Drug, or Both?)
CanadaWe found no product containing palmitoyl pentapeptide-4 in Health Canada’s Drug Product Database (searched 2026-10-01). (Health Canada: Health Canada Drug Product Database search: matrixyl — no product found)
Sport (WADA)WADA’s Prohibited List does not name palmitoyl pentapeptide-4. WADA states that topical cosmetic products may contain prohibited peptides or growth factors and that using cosmetic products containing such substances is prohibited; we found no WADA statement on whether palmitoyl pentapeptide-4 is one of them. (WADA: World Anti-Doping Code International Standard Prohibited List 2026; WADA: World Anti-Doping Agency Prohibited List)

Official sources: FDA: Is It a Cosmetic, a Drug, or Both? · WADA: World Anti-Doping Code International Standard Prohibited List 2026 · WADA: World Anti-Doping Agency Prohibited List

Report a side effect

If something went wrong after using any product, tell a clinician and report it. Reports are how regulators find contaminated or mislabeled products.

FDA MedWatch (United States)
Canada Vigilance Program (Canada)

Common questions

Does Matrixyl work?

Is Matrixyl a copper peptide?

Expert review It contains no copper: pal-KTTKS is a palmitoyl pentapeptide ^[1] whose KTTKS sequence comes from type I procollagen ^[4].^[3][4][1]

How long does Matrixyl take to work?

The human studies cited here measured results after 12 weeks, 8 weeks. That is how long the studies ran, not a promise of results.^[1][2]

References

Every reference below was matched to its PubMed or DOI record (title checked) before publication. "Verified" means the paper exists and is the one named; what it supports is stated next to each claim.

Topical palmitoyl pentapeptide provides improvement in photoaged human facial skin. Int J Cosmet Sci (2005). PubMed 18492182 DOI
Double-blind, Randomized Trial on the Effectiveness of Acetylhexapeptide-3 Cream and Palmitoyl Pentapeptide-4 Cream for Crow's Feet. J Clin Aesthet Dermatol (2023). PubMed 36909866
Topically applied KTTKS: a review. Int J Cosmet Sci (2011). PubMed 21535443 DOI
A pentapeptide from type I procollagen promotes extracellular matrix production. J Biol Chem (1993). PubMed 8486721 DOI
Dermal Stability and In Vitro Skin Permeation of Collagen Pentapeptides (KTTKS and palmitoyl-KTTKS). Biomol Ther (Seoul) (2014). PubMed 25143811 DOI
Oral and topical peptides for skin aging: systematic review and meta-analysis of randomized controlled trials. Front Med (Lausanne) (2026). PubMed 41924746 DOI

Written by SoftMaxx AI editorial · Citations checked against PubMed records · Updated 2026-10-01 · Not medically reviewed. Editorial standards · Evidence grading and update log.