Adverse effect · Matrixyl

How common is safety with Matrixyl?

C
Grade C — weak human evidence1 RCT (n=93, 12 wk) · effect size: not measurable · adverse
Short answerWeak human evidence. 1 RCT (n=93, 12 wk): enough to be interesting, not enough to count on. Where an effect is seen it is no measurable effect, or none yet shown. The trial reported the peptide was well tolerated by the skin over twelve weeks. Decades of cosmetic use at parts-per-million concentrations have produced no safety signal.

What the studies show

The trial reported the peptide was well tolerated by the skin over twelve weeks. Decades of cosmetic use at parts-per-million concentrations have produced no safety signal.

A few small or poorly-controlled human studies. Enough to be interesting; not enough to count on. Most of what gets called “clinically proven” online lives here.

  1. 1
    Robinson LR, Fitzgerald NC, Doughty DG, Dawes NC, Berge CA, Bissett DL. Topical palmitoyl pentapeptide provides improvement in photoaged human facial skin.Int J Cosmet Sci, 2005;27:155–16093 women aged 35–55; 12-week double-blind split-face study of 3 ppm pal-KTTKS versus vehicle. Procter & Gamble authors.

In context

Matrixyl is palmitoyl pentapeptide-4 (pal-KTTKS), a five-amino-acid fragment of type I collagen with a palmitic acid tail added so it can cross the skin barrier. Its human evidence is a 93-woman, 12-week, split-face randomised trial run by Procter & Gamble, which found significant reduction in wrinkles and fine lines against the vehicle control by both instrumental and expert-grader analysis. It is a legal cosmetic ingredient everywhere LYO covers and is not a medicine.

Matrixyl is cosmetic ingredient. Legal status differs by country — see the regulation section or the jurisdiction pages.

Questions

Is Matrixyl proven to cause safety?
No. The human evidence is weak (1 RCT (n=93, 12 wk)); LYO grades it C.
What studies are behind the grade?
The trial reported the peptide was well tolerated by the skin over twelve weeks. Decades of cosmetic use at parts-per-million concentrations have produced no safety signal.
Is Matrixyl approved for this?
No. Matrixyl is cosmetic ingredient; it is not an approved medicine for any indication in the jurisdictions LYO covers.

Other outcomes for Matrixyl

Written and maintained by LYO Research — how pages are written and checked. Reviewed 29 October 2026. Grades count human evidence only; see how LYO grades. Not medical advice. Correct this page →