Tissue Repair & Regeneration

Pentapeptide-18

Leu-enkephalin is one of the body's own opioid-like messengers, and pentapeptide-18 — sold as Leuphasyl — is a five-amino-acid copy of it, put into creams on the idea that binding enkephalin receptors at a nerve terminal will quiet the signal that creases an expression line. It is usually paired with Argireline, the argument being that the two damp the same nerve traffic by different routes. This record's evidence tier is computational: the two graded studies on file are a molecular modelling paper and a computer safety screen. No human or animal study of the peptide is held here, and the wrinkle-depth figures on ingredient pages come from the supplier.

Last updated 12 August 2026

Studied forExpression line research · Skin texture context · Pigmentation research

Evidence on file2 computational studies · 1 citation not yet graded

Strongest sourcePentapeptide-18 as an anti-aging candidate: Spectroscopic characterization and molecular interaction analysis. (computational study)

Mechanism

Binds enkephalin receptors on nerve terminals, lowering neurotransmitter release; also studied for reduced tyrosinase activity.

Reported effects

What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.

Expression line research
Skin texture context
Pigmentation research

Manufacturer’s claim vendor marketing

For a proprietary cosmetic ingredient the manufacturer is the originator — there is no upstream to defer to, and this is often the only description that exists. It is reproduced as an attributed claim, with the label its source gave it. It is not graded and it is not evidence — the graded studies are under Literature.

Vendor claims quoted from fetched page (ci.guide): "it couples to the enkephalin receptor on the outside of the nerve cells, relaxing expression muscles and smoothing wrinkles"; "less effective than Botox injections, but it is safe, has no adverse effects, and preserves facial expressivity"; combined with Argireline it "showed a potentiating effect, yielding more noticeable results". No n= or duration on fetched page.

Manufacturer: Not confirmed on fetched pages (Lipotec/Lubrizol hypothesis not verified; a guessed Lubrizol product URL returned 404)
Sold as: Leuphasyl
Manufacturer’s recommended use: Not specified on fetched page

Source page — nofollow, because a vendor link is a reference here, not an endorsement.

Dosing on file unverified

0.5-5% in serums/creams, 2x/day

Carried from a source that labels it unverified, and reproduced with that label attached. A record of what is reported, not a recommendation. No citation on this page establishes it.

Literature on file 5

review or editorial
Peptides: Emerging Candidates for the Prevention and Treatment of Skin Senescence: A Review. graded on: indexed as "review-article" - secondary literature, not a study — “review-article”
review or editorial
Acetyl Hexapeptide-8 in Cosmeceuticals-A Review of Skin Permeability and Efficacy. graded on: indexed as "review-article" - secondary literature, not a study — “review-article”
computational
Pentapeptide-18 as an anti-aging candidate: Spectroscopic characterization and molecular interaction analysis. graded on: a computational prediction — read from the indexed abstract — “molecular docking”
computational
A framework for the safety evaluation of peptides in cosmetics. graded on: in-silico safety framework applied through six bioinformatic tools — read from the abstract — “abstract review”

Not graded

1 citation whose study design could not be read from the title. Left ungraded rather than guessed at.

not graded
Solid Lipid Nanoparticles Incorporated with Retinol and Pentapeptide-18—Optimization, Characterization, and Cosmetic Application (2024, cited 19x)

Identity

Space-filling 3D model of Pentapeptide-18, carbon grey, nitrogen blue, oxygen red — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

2D chemical structure of Pentapeptide-18 — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

Molecular weight: 569.6
Molecular formula: C29H39N5O7
CAS number: 64963-01-5
PubChem CID: 10099522
InChI key: ZHUJMSMQIPIPTF-JMBSJVKXSA-N
SMILES: C[C@H](C(=O)NCC(=O)N[C@@H](CC1=CC=CC=C1)C(=O)N[C@@H](CC(C)C)C(=O)O)NC(=O)[C@H](CC2=CC=C(C=C2)O)N
InChI: InChI=1S/C29H39N5O7/c1-17(2)13-24(29(40)41)34-28(39)23(15-19-7-5-4-6-8-19)33-25(36)16-31-26(37)18(3)32-27(38)22(30)14-20-9-11-21(35)12-10-20/h4-12,17-18,22-24,35H,13-16,30H2,1-3H3,(H,31,37)(H,32,38)(H,33,36)(H,34,39)(H,40,41)/t18-,22+,23+,24+/m1/s1

Also called

Leuphasyl
Pentapeptide-18

Notes unverified prose

Clinical trial (n=20, 0.5-2%, 2 months): 2% showed significant wrinkle improvement; 28-day (n=14, 5%): wrinkle depth -11.64%; Clinical trial: 5% reduced wrinkle depth 11.64% at 28 days; 0.5-2% study

Not on file 2

1 of the 8 fields we track hold nothing on this record, and each says why. 1 further absence is named below. A blank field is a bug; a named absence is a finding.

amino-acid sequencenothing we hold supplies it
half-lifenothing we hold supplies it

Each field links to every other record missing the same thing. The full ledger holds 765 gaps across 163 records.

Listed prices 6

What 6 shops we track listed for Pentapeptide-18, read from their own public catalogues on 2026-09-14. We take no commission on these and they are not ranked by any payment — how vendors are scored.

Compare prices6 listings from 6 shops

Listed in USD
Vendor	Size	Price	Per mg
Core Peptides	200 mg	$176.00 USD	$0.88/mg
Raw Amino	200 mg	$212.00 USD	$1.06/mg
Biotech Peptides	200 mg	$215.00 USD	$1.07/mg
USA Peptide Sciences	200 mg	$230.00 USD	$1.15/mg

Listed in CAD
Vendor	Size	Price	Per mg
Peptide Shop Canada	200 mg	$140.70 CAD	$0.70/mg
Core Peptides Canada	200 mg	$217.01 CAD	$1.09/mg

Prices are the vendor's own listing, reproduced with the date we read it — never converted between currencies, and compared per milligram only where the vendor states the vial size.