Palmitoyl pentapeptide-4: fewer wrinkles and fine lines in 12 weeks
Clinical trial3 ppm (0.0003%)12 weeks93 women aged 35 to 55Double-blind, split-face
Significant improvement in wrinkles and fine lines versus placebo, by instrumental image analysis and by expert grading. The peptide is well tolerated. Trial run by a manufacturer3.
Acetyl hexapeptide-8: eye-area wrinkles in 4 weeks
Clinical trial2 applications a day4 weeks60 Chinese volunteersRandomized, 3 to 1 versus placebo
Overall anti-wrinkle efficacy of 48.9% in the peptide group, versus 0% under placebo. Roughness measured on silicone replicas drops under the peptide, not under placebo4.
Tetrapeptide-30: less visible dark spots, in combination
Clinical trialPeptide + vitamin C derivative6 to 8 weeks39, 19 and 27 volunteersDouble-blind versus vehicle
Facial dark spots fade after 6 weeks with the combination, more than with the peptide or the vitamin C derivative alone. In 27 Japanese women, the combination reduces pigmentation by 26% and 18% depending on the SCINEXA score. In the lab, the peptide limits the expression of pigmentation genes after UVB5.
Palmitoyl tripeptide-38: an antioxidant serum, more even-looking skin
Clinical trial5 ppm (0.0005%) with 15% vitamin C and tocopheryl acetate56 days, once a dayOpen-label, no placeboWomen aged 40 and over
Roughness down 8 to 9%, redness reduced by 9% and skin tone evenness up 8%. The peptide's own effect is not separated from that of the serum's antioxidants. Authors are consultants for the serum brand6.
Copper tripeptide-1: mostly narrative evidence
Review2015 narrative review
The GHK tripeptide forms a complex with copper. In cosmetics, the review reports better skin elasticity, density and firmness, and fewer fine lines. It details no trial here, and its authors are affiliated with the company Skin Biology7.