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Cosmetic and topical
Skin & aging
Palmitoyl tripeptide-38
Palmitoyl tripeptide-38 is a cosmetic signal peptide sold as Matrixyl synthe'6. See how it works, what human evidence exists, and its regulatory status.
- Reviewed by
- William Maish, MD MBA MPH, Clinical Product Lead
- Published
- October 5, 2026
- Last updated
- October 5, 2026
Key takeaway
Palmitoyl tripeptide-38 is a fat-attached "signal" peptide, sold as Matrixyl synthe'6, designed to prompt skin cells to make several different matrix building blocks. Laboratory and manufacturer work report that it can stimulate collagen and other structural components, which is the basis for its use in products aimed at the appearance of smoother, firmer skin. As of 2026, the human evidence is limited to one open-label human study of a combined vitamin-and-peptide serum, so the ingredient's individual effect is not established.
What is palmitoyl tripeptide-38?
Palmitoyl tripeptide-38 is a peptide of three amino acids joined to palmitic acid to aid skin penetration. It is a matrikine-style signal peptide designed to imitate sequences found in the skin's support proteins. It is made by Sederma and sold under the trade name Matrixyl synthe'6, used as its own active rather than as part of the Matrixyl 3000 pairing. It is a cosmetic ingredient, not a drug.
How does it work?
Laboratory studies describe palmitoyl tripeptide-38 as a signal that encourages skin cells to rebuild several matrix components at once. The marketing name "synthe'6" refers to the claim that it stimulates six constituents, the proteins and molecules that give skin and its layers structure and cushioning, including:
- Collagen types I, III, and IV
- Fibronectin
- Hyaluronic acid
- Laminin
The proposed result is a smoother, firmer-looking surface.
These are laboratory and manufacturer findings; the "six-component" claim comes from the ingredient maker's own studies. In finished cosmetics, the benefit is described in appearance terms, such as the look of softened wrinkles.
Is it FDA-approved?
No, and it does not need to be. The FDA does not pre-approve cosmetic ingredients. A cosmetic may describe effects on the appearance of skin, while a claim to rebuild the body's tissues would make a product a drug. Palmitoyl tripeptide-38 is used as a cosmetic ingredient, for the appearance of the skin.
What is it used for?
Palmitoyl tripeptide-38 is used in "anti-aging" serums and creams aimed at the look of forehead lines, crow's-feet, and overall wrinkle appearance, as well as smoother, firmer-looking skin.
What does the research show?
The direct evidence is limited. According to PubMed, one open-label human study1 tested a serum combining palmitoyl tripeptide-38 with vitamins C and E and reported reduced skin roughness and improved tone over about two months. Because the serum also contained a high concentration of vitamin C, a potent active in its own right, and because the study had no control group, the peptide's individual contribution cannot be isolated. The remaining efficacy data are manufacturer studies. No independent, controlled single-ingredient trial was found.
What are the side effects?
Palmitoyl tripeptide-38 is generally reported as well tolerated on the skin, and the combined-serum study above reported no notable adverse reactions. As with any new product, a patch test is sensible for sensitive or reactive skin.
Sources: an open-label study of a vitamin-and-peptide serum (Lintner et al., Journal of Cosmetic Dermatology, 2020, DOI: 10.1111/jocd.137701), indexed on PubMed; and manufacturer and cosmetic ingredient reference data on Matrixyl synthe'6. This document is educational and does not constitute medical advice.