# Matrixyl (Palmitoyl Pentapeptide-4)

> Palmitoylated matrikine peptide that signals fibroblasts to synthesize collagen — contains no copper.

- Also known as: Palmitoyl Pentapeptide-4, Pal-KTTKS, Matrixyl
- Class: Cosmetic
- FDA approved: No
- Canonical page: https://www.americanpeptide.com/catalog/matrixyl

## Overview

Matrixyl is palmitoyl pentapeptide-4 (Pal-KTTKS), a lipidated peptide whose KTTKS core is a fragment of type-I procollagen. Rather than delivering copper, it acts as a matrikine signal that stimulates extracellular-matrix synthesis.

Matrixyl is the trade name for palmitoyl pentapeptide-4, a five-amino-acid sequence (KTTKS) joined to a palmitic-acid chain that improves skin penetration. The KTTKS sequence is a fragment naturally cleaved from the C-terminal propeptide of type-I procollagen during collagen assembly.

The body uses that fragment as a feedback signal — a "matrikine" — telling fibroblasts to keep producing matrix. Matrixyl exploits this: it is studied not as a copper peptide but as a signaling molecule that drives collagen synthesis, and it is one of the better-evidenced cosmetic peptide ingredients.

## Mechanism

Matrikine signaling — mimics a procollagen-I fragment to upregulate collagen and fibronectin synthesis.

## Chemistry

| Property | Value |
| --- | --- |
| Molecular weight | 802 Da |
| CAS number | 214047-00-4 |

## Sequence

```
KTTKS
```

## Research areas

Studied in: Skin aging, Collagen synthesis.

Guides on this site:

- [Skin & Hair](https://www.americanpeptide.com/research-areas/skin-hair): Peptides studied for skin aging, pigmentation, and hair follicle biology.

## Key research

- Matrikine signaling — the KTTKS core mimics a procollagen-I breakdown fragment, signaling fibroblasts to upregulate collagen I, collagen IV, and fibronectin.
- Clinical cosmetic data — a 12-week split-face randomized controlled trial (Robinson et al., 2005) reported improvements in wrinkle depth and skin roughness at low concentration.
- Palmitoylation — the lipid chain improves penetration of the otherwise hydrophilic peptide through the stratum corneum.
- Compared to copper peptides — unlike GHK-Cu or AHK-Cu, Matrixyl contains no copper and works purely by signaling, not metal delivery.
- Cosmetic ingredient — topical use; not a drug.

## Storage, handling & synthesis

**Storage.** Store the lyophilized peptide frozen and protected from light; in cosmetic formulation, follow the product’s stability guidance.

**Handling.** Palmitoylation makes it amphiphilic — disperse carefully in formulation. Protect from heat and light.

## FAQs

### What is Matrixyl?

Matrixyl is palmitoyl pentapeptide-4 (Pal-KTTKS), a lipidated peptide whose KTTKS core is a procollagen-I fragment that signals fibroblasts to produce collagen. It is a widely used cosmetic ingredient.

### Is Matrixyl a copper peptide?

No. Unlike GHK-Cu and AHK-Cu, Matrixyl contains no copper. It works as a matrikine signal, not by delivering a metal.

### What is the evidence for Matrixyl?

A 12-week split-face randomized controlled trial (Robinson et al., 2005) reported improvements in wrinkle depth and skin roughness, making it one of the better-evidenced cosmetic peptides.

### How does it work?

Its KTTKS sequence mimics a collagen-breakdown fragment, signaling fibroblasts to upregulate collagen I, collagen IV, and fibronectin synthesis.

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Source: AmericanPeptide.com — https://www.americanpeptide.com/catalog/matrixyl
Data license: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Attribution: AmericanPeptide.com.
Research reference only — computational and educational content, not medical advice.