Argireline (acetyl hexapeptide-8)

Argireline is a cosmetic ingredient, acetyl hexapeptide-8 (formerly acetyl hexapeptide-3), a six-residue peptide modeled on the N-terminal region of the SNARE protein SNAP-25. It has been studied in vitro and in small cosmetic trials of expression lines.

Last reviewed 2026-10-25 by the PeptideWiki editorial team. Editorial policy.

Overview

Argireline is the trade name for acetyl hexapeptide-8, an INCI-listed cosmetic ingredient previously labeled acetyl hexapeptide-3. Its sequence was designed to mimic part of the N-terminal region of SNAP-25, a component of the SNARE complex that mediates release of neurotransmitter vesicles. The idea behind it was to interfere, in a much weaker and topical way, with the same machinery that botulinum toxin type A disrupts by cleaving SNAP-25, and thereby influence muscle contraction involved in expression lines.

Argireline is used in topical cosmetic formulations and is one of the most widely known cosmetic peptides. Its supporting research consists of in-vitro experiments on SNARE complex assembly and neurotransmitter release in cultured cells, together with small cosmetic studies measuring wrinkle depth or skin topography. Penetration of a charged hexapeptide through intact skin to the neuromuscular junction is a key open question. It is not a drug, and cosmetic findings should not be read as evidence of medical effects.

Compare: Argireline vs Matrixyl.

Structure

Argireline is a hexapeptide with the sequence Ac-Glu-Glu-Met-Gln-Arg-Arg-NH2 (Ac-EEMQRR-NH2), with an N-terminal acetyl group and a C-terminal amide. The sequence corresponds to a short stretch of the N-terminal region of SNAP-25. It is highly charged, with two glutamates and two arginines, and quite hydrophilic. The methionine residue is susceptible to oxidation to methionine sulfoxide. A related octapeptide, acetyl octapeptide-3 (Snap-8), extends the same sequence by two residues. Cosmetic-grade material is usually an acetate salt.

Mechanism

The proposed mechanism is competition with SNAP-25 during assembly of the SNARE complex, which contains SNAP-25, syntaxin and synaptobrevin and is needed for vesicle fusion and neurotransmitter release. In in-vitro studies, the peptide was reported to destabilize complex formation and reduce release of catecholamines from cultured chromaffin cells. Whether topically applied argireline reaches nerve terminals in sufficient amounts to act this way in skin has not been established, and other contributions to reported cosmetic effects, such as formulation and hydration, are difficult to exclude.

Research

In-vitro SNARE studies

The founding work on argireline examined its effects on SNARE complex formation in reconstituted systems and on regulated exocytosis in cultured neuroendocrine cells, reporting inhibition at research concentrations. These experiments establish that the sequence can interfere with SNARE assembly in vitro. They do not show what concentrations reach target tissues after application to skin, which is the central gap between the mechanistic and cosmetic literature.

Cosmetic studies of expression lines

Small studies in volunteers, often sponsored by ingredient developers or formulators, have measured periorbital and forehead wrinkles using silicone replicas, profilometry or imaging after topical use of argireline-containing preparations. Some reported reductions in wrinkle measures relative to baseline or vehicle. These studies are typically short, small and not always blinded or independently replicated, and they assess cosmetic appearance rather than medical outcomes. Many results are presented in industry technical documents rather than in independent peer-reviewed journals, which makes appraisal of methods and data more difficult.

Skin penetration

Studies of skin permeation have examined how much argireline crosses the stratum corneum and reaches deeper layers, generally finding limited penetration of this charged, hydrophilic peptide, with most remaining in the upper skin. Formulation approaches have been investigated to improve delivery. These findings bear directly on the plausibility of the proposed neuromuscular mechanism in skin. Experimental conditions, such as excised versus living skin and the vehicle used, strongly affect such measurements.

Evidence quality

Argireline has a plausible molecular rationale and a body of in-vitro work, but the cosmetic evidence is limited in size and independence. Comparisons to botulinum toxin are mechanistic analogies rather than demonstrations of similar effect, since the toxin enzymatically cleaves SNAP-25 inside nerve terminals after injection. Researchers should frame argireline as a cosmetic ingredient with modest, small-study evidence. Larger independent trials are lacking.

Regulatory status

Argireline is a cosmetic ingredient listed under the INCI name acetyl hexapeptide-8 (formerly acetyl hexapeptide-3). It is not an FDA-approved drug and is not intended to treat any condition. In the United States, products containing it are regulated as cosmetics, and claims that a product affects body structure or function can cause it to be regarded as a drug. Cosmetic ingredient regulations differ in other jurisdictions.

Status changes often. See the regulatory tracker for dated updates.

Quality and identity testing

A certificate of analysis should confirm identity by mass spectrometry, with the observed mass matching the expected mass shown on this page for the acetylated and amidated hexapeptide, and report HPLC purity with the chromatogram. Compound-specific checks include methionine oxidation, which adds about 16 Da, deamidation of the glutamine residue, and the presence of the correct acetyl and amide termini. Because cosmetic raw material is often supplied as a solution in a carrier, the COA should state peptide concentration as well as purity. Confusion with acetyl octapeptide-3 (Snap-8) is possible and is resolved by mass.

Open Argireline (acetyl hexapeptide-8) in the sequence analyzer to see the expected [M+H]⁺ and multiply charged ions for an MS identity check (set the N-acetyl, amide and disulfide options to match).

For a walkthrough of each section of a certificate, see how to read a COA.

Storage and stability

Store lyophilized argireline sealed at -20 °C or in refrigerated conditions as indicated on its documentation, protected from light and moisture, and let containers reach room temperature before opening. The methionine residue is prone to oxidation, so limit air exposure, avoid oxidizing excipients and consider inert-gas overlay for stock solutions. It dissolves readily in water. Aliquot solutions for lab use, store them cold, and avoid repeated freeze-thaw cycles.

Download the Argireline (acetyl hexapeptide-8) data sheet (PDF): sequence, masses, expected MS ions and handling on one printable page.

Latest research

Frequently asked questions

Related compounds

• Snap-8

  Snap-8, or acetyl octapeptide-3, is a synthetic eight-residue cosmetic peptide, Ac-EEMQRRAD-NH2, modeled on the N-terminal region of the SNARE protein SNAP-25. It is studied mainly in vitro and in cosmetic formulation research.

• Matrixyl (palmitoyl pentapeptide-4)

  Matrixyl is a cosmetic ingredient, palmitoyl pentapeptide-4 (Pal-KTTKS), consisting of the pentapeptide Lys-Thr-Thr-Lys-Ser linked to palmitic acid. Its research consists mainly of in-vitro collagen synthesis studies and small cosmetic studies of skin appearance.

• GHK-Cu

  GHK-Cu is the copper(II) complex of GHK (glycyl-histidyl-lysine), a tripeptide found in human plasma. It is widely used as a cosmetic ingredient and studied in cell, animal and small human skin studies.

References

1. PubMed: all indexed literature on Argireline (acetyl hexapeptide-8)
2. ClinicalTrials.gov: registered studies mentioning Argireline (acetyl hexapeptide-8)