Pentapeptide-18
Also referenced as: Leuphasyl
An enkephalin-inspired cosmetic peptide used in wrinkle products.
- Evidence grade
- EExperimental / Limited Evidence
Experimental / Limited Evidence
- Regulatory status
- Not FDA Approved
A cosmetic ingredient, not an FDA-approved anti-aging drug. Cosmetic marketing and ingredient safety reviews do not establish injectable safety or therapeutic approval.
- Human data
- No
No registered clinical trials identified
- Last reviewed
- October 27, 2026
Overview
An enkephalin-inspired cosmetic peptide used in wrinkle products.
A cosmetic ingredient, not an FDA-approved anti-aging drug. Cosmetic marketing and ingredient safety reviews do not establish injectable safety or therapeutic approval.
A proposed receptor effect is not proof of a clinically meaningful wrinkle reduction.
Why It's Being Studied
- Wrinkle appearance
- Neurotransmission hypotheses
Mechanism of Action
It is proposed to reduce neuronal excitability and neurotransmitter release; reliable action through intact skin remains uncertain.
It is proposed to reduce neuronal excitability and neurotransmitter release; reliable action through intact skin remains uncertain. A proposed receptor effect is not proof of a clinically meaningful wrinkle reduction.
Skin remodelling and the hair cycle
Tap each stage to see what happens.
Background: Skin & Hair Research
Skin and hair research looks at collagen synthesis, wound closure, pigmentation and the hair-follicle cycle.
Topical cosmetic research is often industry-funded and small. Injected use of cosmetic peptides has little human data.
Research Areas & Routes Studied
- Wrinkle appearance
- Neurotransmission hypotheses
- Topical cosmetic formulations
Evidence Summary
Combination-product cosmetic studies do not establish a standalone treatment effect.
Higher tiers carry more weight. Filled tiers have evidence for Pentapeptide-18; tap to read it.
No evidence at this tier is summarised for Pentapeptide-18. Absence of data is not evidence of safety or benefit.
2 cited sources.
- Narrative review1
- Regulatory document1
Evidence limitations
- Combination-product cosmetic studies do not establish a standalone treatment effect.
Reported Adverse Events in Research
- Local irritation is possible; injectable neuromuscular safety and efficacy are not established.
Limitations of Current Evidence
- A proposed receptor effect is not proof of a clinically meaningful wrinkle reduction.
- Findings apply to the product, route and population studied; they do not establish benefits or safety for unrelated wellness uses or research-vial products.
How to Read This Research
- Was the product topical or injected?
- Were results measured by instruments or by photos and self-assessment?
- Who funded the study?
- Cosmetic claims face a lower evidence bar than medical claims.
- Pigmentation-affecting compounds carry documented risks, including changes in moles.
- Anagen
- The active growth phase of a hair follicle.
- Dermis
- The skin layer beneath the surface that holds collagen.
- Melanocortin
- A hormone family that affects pigmentation and appetite.
Compare With Other Compounds
| Pentapeptide-18 | GHK-Cu | |
|---|---|---|
| Evidence grade | E — Experimental / Limited Evidence | C — Early Human Research |
| Regulatory status | Not FDA Approved | Not FDA Approved |
| Human data | No | Limited |
| Clinical trials | None identified | None identified |
| Research routes | Topical cosmetic formulations | Topical, Intradermal (cosmetic research) |
| Cited sources | 2 | 2 |
Frequently Asked Questions
Research References
- Narrative review
Cosmetic peptide research and delivery limitations
- Regulatory document
FDA: cosmetics are not preapproved medicines