Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library
Leuphasyl (Pentapeptide-18): what the evidence says
At a glance
What it is: a synthetic 5-amino-acid cosmetic peptide (INCI pentapeptide-18, trade name Leuphasyl) said to mimic enkephalins and calm expression lines. R1 UNVERIFIED the sequence Tyr-D-Ala-Gly-Phe-Leu against a peer-reviewed source.
What the evidence says: spectroscopy, docking and cell-toxicity studies. R1, R2 One small volunteer study used a cream with retinol and the peptide, so the peptide's own effect can't be isolated. R3 No human data for the peptide alone; none for injection.
Biggest risks: unknown; no published safety data for injection.
Rating
| Human Human evidence | Very limited: one multi-ingredient volunteer study R3 |
| Animal Animal / lab evidence | Spectroscopic, docking and cell studies R1, R2; formulation R4 |
| Regulatory | Cosmetic ingredient, not a drug · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page · not named on WADA's 2026 list R5, R6, R7, R8 |
| Established human dose | None |
Evidence verdict: Wrinkles (cream): Very limited (lab and computer models; one multi-ingredient product study) · Injection: No human data
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: we found no peer-reviewed split-face or controlled trial of Leuphasyl alone. UNVERIFIED supplier-reported trial results.
What is it?
Leuphasyl is marketed as a "Botox-like" topical peptide, often blended with Argireline. Related pages: Argireline, SNAP-8, Matrixyl, GHK-Cu, Syn-Ake.
Does it work?
- Animal Computer and lab models: binding to skin-aging targets; low cell toxicity. R1, R2
- Animal Formulation: stable in lipid nanoparticles with retinol. R4
- Human Volunteer study of a retinol-plus-peptide product: fewer wrinkles, but the peptide's share is unknown. R3
- Unknown Leuphasyl alone in people: no peer-reviewed data.
Is it safe?
- Unknown No peer-reviewed safety data; injection never studied.
Gray-market "Leuphasyl" 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; not an approved drug; not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. R5, R6, R7
Study details
Study details
These are amounts researchers used, not recommendations.
| Study | People / model | Route | Amount used | Follow-up | Reported | Citation |
|---|---|---|---|---|---|---|
| Retinol + peptide products 2024 | Volunteers | Topical | Not reported for the peptide alone | Per study | Fewer wrinkles (whole product) | PMID 39459512 |
| Lab / in-silico 2026 | Models and cells | In vitro | Not applicable | Not applicable | Binding, low toxicity | PMID 42116636 |
Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 26, 2026)
- R1 Akhan D, et al. Comput Biol Chem. 2026. PMID 41722287
- R2 Akhan D, et al. Chem Biodivers. 2026. PMID 42116636
- R3 Pawłowska M, et al. Life (Basel). 2024. PMID 39459512
- R4 Pawłowska M, et al. Int J Mol Sci. 2024. PMID 39337562
- R5 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
- R6 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
- R7 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
- R8 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 Leuphasyl (Pentapeptide-18). Leuphasyl is a cosmetic ingredient. It has never been tested as an injection. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).