Palmitoyl pentapeptide-4 vs Acetyl octapeptide-3
It is put in anti-wrinkle creams, often under the name Matrixyl, to smooth fine lines. One trial of 93 women showed a small gain, but the maker ran it and no one else has repeated it. A face-cream ingredient sold to smooth lines around the eyes and forehead. It has not been properly tested on its own; one 24-person study used a mixed product.
Palmitoyl pentapeptide-4 has the stronger evidence, grade B (some human evidence) against grade C for Acetyl octapeptide-3. Neither is FDA approved.
Evidence
BSome human evidence
CAnimal and cell studies
Human studies cited
Animal or cell studies cited
Why the grade
One randomized, double-blind, placebo-controlled split-face trial in 93 women showed a measurable reduction in fine lines and wrinkles over 12 weeks, backed by a 1993 cell study identifying the five-amino-acid sequence as a stimulator of collagen production. The trial was run by the manufacturer and has not been independently replicated, which caps it at B.
The only peer-reviewed human study found that tests a product containing SNAP-8 is a 2024 split-face study in 24 people, in which a microneedle patch carrying SNAP-8 together with other actives was compared with a plain hyaluronic acid patch for 28 days. SNAP-8 has not been tested on its own against placebo, and the claim that it beats Argireline comes from the manufacturer. That is grade C.
FDA
Cosmetic ingredient
Palmitoyl pentapeptide-4 is a cosmetic ingredient, sold under trade names such as Matrixyl. It is not approved by the FDA as a drug for any use; the FDA regulates cosmetics but does not approve their ingredients.
Cosmetic ingredient
Acetyl octapeptide-3 (SNAP-8) is a cosmetic ingredient. The FDA does not approve cosmetic ingredients before sale and regulates products containing it as cosmetics provided they claim only to improve appearance; it is not an approved drug for any use.
Sold for
Palmitoyl pentapeptide-4, better known as Matrixyl, is the peptide most anti-wrinkle creams point to when they say peptides work.
SNAP-8 is sold as a longer, stronger version of Argireline that relaxes expression lines around the eyes and forehead when applied topically.
Studies say
A single sponsor-run randomized trial found modest wrinkle improvement versus the same moisturizer without the peptide, which is better evidence than most cosmetic peptides have and still short of independent confirmation.
The mechanism is borrowed from Argireline and the clinical support is one 24-person study of a microneedle patch that mixed SNAP-8 with other actives, which is too little to say SNAP-8 itself reduces wrinkles (grade C).
Class
Signal (collagen) peptide
Neurotransmitter-inhibiting peptide
Route
Topical
Topical