Library / Skin and hair

Palmitoyl pentapeptide-4

Also known as Matrixyl, Pal-KTTKS, Palmitoyl oligopeptide

Human trials

Lipid linked pentapeptide used in topical anti ageing skin care, intended to support collagen production. Evidence is from small cosmetic studies of creams, not medical trials.

Not an approved medicine. Palmitoyl pentapeptide-4 is not an approved medicine for this use in Australia or the United States. This page summarises published research for information only. It is not a recommendation to use Palmitoyl pentapeptide-4, and VialOwl does not sell or supply it.

Background

Palmitoyl pentapeptide-4 is the collagen fragment KTTKS (lysine, threonine, threonine, lysine, serine) with a fatty acid (palmitic acid) attached to help it penetrate skin. It was developed as a cosmetic ingredient and sold under the trade name Matrixyl, and has been used in anti wrinkle creams since the early 2000s.

How it is thought to work

KTTKS is a small piece of type I procollagen. Lab work suggested fragments like this act as a signal to skin cells to make more collagen and other matrix proteins; the fatty acid tail helps it reach the skin cells from a cream.

What is claimed, and the evidence

Claim	Evidence	Notes
Reduced fine lines and wrinkles in photoaged facial skin (topical)	Human trials	A 12 week split face randomised trial in 93 women found improvement over the same moisturiser without it; the study was run by a cosmetics manufacturer.
Reduced crow's feet (topical)	Small human studies	Small randomised trial of 21 women over 8 weeks; authors call it an initial study needing larger samples.
Collagen rebuilding when injected or taken orally	No published evidence	No published evidence; it is a cosmetic ingredient designed for creams.
Results comparable to retinoids or cosmetic procedures	No published evidence	Marketing claim; no head to head trials found.

Side effects

Effect	How often	Notes
Skin irritation	Uncommon	Reported as well tolerated in published cosmetic trials.
Effects of injected or non topical use	Frequency unknown	No published data.

Warnings

Evidence is limited to small cosmetic studies of creams, some funded by manufacturers.
Not intended for injection; injectable products are unapproved and carry purity and sterility risks.

Regulatory status

Australia: Cosmetic ingredient. Not included on the ARTG as a medicine and not listed in the Poisons Standard (June 2026).
United States: Cosmetic ingredient; not an FDA approved drug.

Sources

Also in Skin and hair

From the VialOwl library, reviewed 26 September 2026. For education and general information. It is not medical advice and not a recommendation to use Palmitoyl pentapeptide-4.