Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library
Acetyl tetrapeptide-5 (Eyeseryl): what the evidence says
At a glance
What it is: a short synthetic peptide (acetyl-β-alanine-histidine-serine-histidine) sold under the trade name Eyeseryl for eye creams. Its first two building blocks match carnosine. R1
What the evidence says: ⚪ no peer-reviewed human trial was found. The only study found tested it in lab-grown skin cells, mixed with other peptides. R2 Manufacturer claims about puffiness could not be checked against published data. UNVERIFIED
Biggest risks: unknown. Cosmetic use on the skin is generally low-risk, but no published human safety data were found for this peptide.
Rating
| Human Human evidence | No human data: none found |
| Animal Animal / lab evidence | Very limited: one cell study of peptide mixtures R2 |
| Regulatory | Cosmetic ingredient; not FDA-approved R3 · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page R4, R5, R6 · not named by WADA R7 |
| Established human dose | No |
Evidence verdict: Under-eye puffiness and dark circles: No human data (no peer-reviewed human trial found) · Lab studies: one skin-cell study of peptide mixtures
This page reports what studies used. It is not dosing advice.
Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source
About the evidence: the evidence is limited to lab cells; nothing has been shown in people.
What is it?
Related pages: argireline, snap-8, ghk-cu, carnosine.
Does it work?
- ⚪ Under-eye puffiness or dark circles: no peer-reviewed human trial found.
- 🧪 Lab: in skin fibroblasts, it was tested for effects on an enzyme (ACE-1) as part of a mixture study. R2
Is it safe?
- No published human safety data found.
- Patch-test any new eye-area product; stop if irritation develops.
Gray-market vials: extra risks
A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.
Is it legal?
- US: sold as a cosmetic ingredient. Cosmetics do not need FDA approval before sale; products making drug-type claims can be regulated as drugs. R3 No Drugs@FDA application found (openFDA searched Oct 27, 2026).
- Compounding: not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. R4, R5, R6
- Sport: not named on WADA's 2026 Prohibited List. R7
Study details
Study details
These are amounts researchers used, not recommendations.
| Study | People / model | Route | Amount used | Follow-up | Reported | Citation |
|---|---|---|---|---|---|---|
| Wu 2021 (lab) | Human skin fibroblasts | In vitro | 100 µg/mL tested | Lab | ACE-1 activity measured; tested in peptide mixtures | PMID 33849044 |
Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)
- R1 PubChem CID 11620163, Acetyl tetrapeptide-5 (synonyms include Eyeseryl and Ac-β-Ala-His-Ser-His-OH), checked Oct 27, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/11620163
- R2 Wu Y, et al. Skin Pharmacol Physiol. 2021. PMID 33849044
- R3 FDA. Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?) Content current as of Sep 11, 2024. https://www.fda.gov/cosmetics/cosmetics-laws-regulations/it-cosmetic-drug-or-both-or-it-soap
- R4 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
- R5 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
- R6 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
- R7 WADA. The 2026 Prohibited List, full list checked; compound not named. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
Disclaimer
This page is for education and harm reduction, not medical advice or a recommendation to use Acetyl tetrapeptide-5 (Eyeseryl). This is a cosmetic ingredient, not an FDA-approved drug. Cosmetic products are not reviewed by FDA for effectiveness before sale. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).