Direct Answer
Palmitoyl pentapeptide-4 (pal-KTTKS, the peptide in the cosmetic ingredient Matrixyl) is a lipidated fragment of type I collagen used in skincare. Published primary evidence is largely in vitro and ex vivo (stability, skin-permeation, and fibroblast studies); independent controlled evidence for appearance benefits is limited.
Summary Table
Evidence Level
High
Key Information
Classification
Key Takeaways
- Palmitoyl pentapeptide-4 (pal-KTTKS) is the peptide in the cosmetic ingredient Matrixyl
- Cited evidence is in vitro/ex vivo (stability, permeation, fibroblast behavior)
- Independent controlled evidence for appearance benefits is limited
Scientific Overview
In Plain English
Palmitoyl pentapeptide-4, the peptide in the cosmetic ingredient Matrixyl, is a small collagen-derived fragment attached to a fatty acid to help it sit in the skin. Most published studies are laboratory (cell and skin-permeation) studies; independent human studies on how it changes skin appearance are limited.
Scientific Details
Palmitoyl pentapeptide-4 (pal-KTTKS) is a palmitoylated collagen type I fragment. An in vitro skin study reported that palmitoylation improves its stability and permeation relative to unmodified KTTKS, but in that model it remained in superficial layers and did not penetrate full-thickness skin. A separate in vitro study examined fibroblast-to-myofibroblast behavior in a wound-healing context and cautioned about dose. These laboratory findings do not establish clinical appearance benefits.
How It Works
Pal-KTTKS is a collagen-fragment peptide; laboratory studies describe it in relation to fibroblast behavior and improved skin permeation when palmitoylated. These effects are characterized in vitro and ex vivo, not in controlled clinical appearance studies in the cited sources.
Mechanism of Action
Collagen-fragment signaling
cell
In vitro studies describe pal-KTTKS in relation to fibroblast activity associated with extracellular-matrix turnover.
Skin permeation (palmitoylation)
cell
In a skin-permeation model, palmitoylation increased stability and superficial-layer permeation versus unmodified KTTKS, though full-thickness penetration was not observed.
Evidence Level
Human Evidence
Independent controlled human appearance studies for pal-KTTKS were not among the cited primary sources.
Cell Evidence
In vitro and ex vivo skin studies examined stability, permeation, and fibroblast behavior.
Limitations
Cited evidence is in vitro/ex vivo; the peptide remained in superficial skin layers in a permeation model, and clinical appearance benefits are not established by these sources.
References
- Dermal Stability and In Vitro Skin Permeation of Collagen Pentapeptides (KTTKS and palmitoyl-KTTKS). Biomolecules & Therapeutics.Cell / In Vitrodoi:10.4062/biomolther.2014.053 →
- Effect of Palmitoyl-Pentapeptide (Pal-KTTKS) on Wound Contractile Process in Relation with CTGF and alpha-SMA Expression. Tissue Engineering and Regenerative Medicine.Cell / In Vitrodoi:10.1007/s13770-016-0017-y →
Alternative Names
- Pal-KTTKS
- Matrixyl
- Palmitoyl-KTTKS
- pentapeptide-4
Claim Boundaries
ION BLUE is an educational research aggregator. This content summarizes published scientific literature. It is not medically reviewed, is not medical advice, and is not a recommendation to use any substance. Several peptides discussed are research chemicals not approved for human use. Consult a licensed healthcare provider. This is a cosmetic-ingredient summary; it does not assert clinical appearance benefits and is not a recommendation to use the ingredient for any purpose.
This page summarizes published research and is for informational purposes only; it is not medical advice.