Also known as: Eyeseryl
Acetyl tetrapeptide-5 (trade name Eyeseryl) is a synthetic, acetylated four-amino-acid peptide used as a cosmetic ingredient for the eye-contour area. Published research is sparse and limited to cell and chemistry studies.
The proposed mechanism is inhibition of angiotensin-converting enzyme (ACE), which ingredient literature associates with the appearance of the eye-contour area; this is largely supplier-derived and has limited independent confirmation [3][4]. In a cell study, researchers measured ACE-1 activity in human skin fibroblasts and identified 100 µg/mL as the working concentration for this peptide [1]. Chemistry work shows its histidine residues bind copper(II) ions [2].
| Study | Model | Reported result | Source |
|---|---|---|---|
| Peptide mixtures in senescent fibroblasts [1] | Cell Human skin fibroblasts, hydrogen-peroxide-induced premature senescence | ACE-1 activity measured; mixture containing this peptide lowered malondialdehyde and raised hydroxyproline, elastin, SOD and glutathione peroxidase versus stressed cells. | Peer-reviewed Skin Pharmacol Physiol 2021 |
| Copper(II) binding of Eyeseryl analogs [2] | Cell Coordination chemistry plus human fibroblast and keratinocyte viability | Parent peptide and a sequence-modified analog formed stable copper(II) complexes; neither was toxic to fibroblasts or keratinocytes. | Peer-reviewed Polyhedron 2022 |
| Cosmetic peptides review (2020) [3] | Review Review of cosmetic peptides | Lists ACE inhibition as the stated mechanism; authors report finding no clinical studies supporting topical use. | Peer-reviewed Cosmetics 2020 |
| Cosmeceuticals and peptides review [4] | Review Review of cosmetic peptide classes | Cited by later reviews as a source describing this peptide's eye-contour use and proposed mechanism. | Peer-reviewed Clin Dermatol 2009 |
Human cosmetic studies describe appearance only. Lab results do not establish effects on skin structure.
