SNAP-8

SNAP-8, also called acetyl octapeptide-3, is a synthetic peptide with the sequence Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2. It belongs to a group of cosmetic-research peptides modeled on the N-terminal end of SNAP-25, a protein of the SNARE complex, which drives calcium-dependent release of neurotransmitter from vesicles.

It is two residues longer than acetyl hexapeptide-3 (Argireline), Ac-Glu-Glu-Met-Gln-Arg-Arg-NH2, whose founding paper reported that it interferes with SNARE complex formation and inhibits neurotransmitter release (Blanes-Mira et al., 2002); a review describes SNAP-8 as working the same way (Errante et al., 2020). The peer-reviewed literature on SNAP-8 itself is thin, and this guide says so where it applies.

PubChem CID 76283482 gives the same formula and weight and lists the sequence and aliases; the SNAP-25 alignment is from UniProt entry P60880. A second PubChem record carrying the SNAP-8 trade name (CID 71587832) shows a different formula, C₄₂H₇₂N₁₆O₁₅S at 1073.2 g/mol, from a structure that does not match the sequence, so look the compound up by CAS number.

PubMed holds very little on SNAP-8: two cosmetic microneedle-patch studies in volunteers in which it was one of several ingredients, and a review that describes it largely from manufacturer data. No peer-reviewed cell, tissue or animal study of SNAP-8 on its own appears in PubMed, so most mechanistic evidence comes from the parent hexapeptide. Each summary below states the model used and which compound was tested.

The SNAP-25 mimetic design (parent hexapeptide)

Acetyl hexapeptide-3 came out of a rational design program for a non-toxic alternative to botulinum neurotoxins. In laboratory assays it inhibited neurotransmitter release with a potency similar to botulinum neurotoxin A but much lower efficacy, by interfering with formation or stability of the SNARE complex, and in a 30-day study in healthy women volunteers an emulsion containing it reduced wrinkle depth by up to 30 percent (Blanes-Mira et al., 2002). Models: release and SNARE-complex assays, and human volunteers. Compound tested: the hexapeptide, not SNAP-8.

What is reported for SNAP-8 itself

A 2020 review of cosmetic peptides describes SNAP-8, under the names acetyl octapeptide-1/-3 and acetyl glutamyl heptapeptide-3, as an elongated SNAP-25 mimic that competes with SNAP-25 during SNARE complex assembly and so reduces glutamate release. The only source the review gives for its SNAP-8 figures, including the degree of release inhibition and wrinkle reduction, is the manufacturer's website, not a peer-reviewed study (Errante et al., 2020). Model: literature and manufacturer data.

Microneedle patch studies in volunteers

Two studies with industry-affiliated authors, including a microneedle manufacturer, tested hyaluronic acid microneedle patches that contained acetyl octapeptide-3 together with other actives. A 12-week single-center study combined it with an arginine/lysine polypeptide, palmitoyl tripeptide-5, adenosine and seaweed extracts and reported good tolerability and changes in instrumental skin measures (Avcil et al., 2020).

A second study placed a patch containing it, a vitamin C derivative and a cyclic lysophosphatidic acid on one eye area and a hyaluronic acid-only placebo patch on the other in 24 healthy subjects for 28 days, and reported wrinkle and elasticity changes with no adverse effects (Shin et al., 2024). Because both patches combined several actives, neither study isolates an effect of SNAP-8. Model: healthy human volunteers, cosmetic formulation studies.

Skin penetration (parent hexapeptide)

In excised hairless guinea pig and human skin, most acetyl hexapeptide-8, the same Ac-EEMQRR-amide sequence, washed off the surface after application in an oil-in-water emulsion; about 0.22 percent of the applied amount was found in human stratum corneum, 0.01 percent in epidermis and none in dermis (Kraeling et al., 2015).

Another group attributed the poor permeation to the peptide's size and hydrophilic, zwitterionic character, increased human-skin permeation in vitro with modified analogs and compared glutamate-release inhibition in neurons derived from human dental pulp stem cells (Lim et al., 2018). SNAP-8 is larger, at 1075.2 g/mol, and no permeation study of it appears in PubMed. Models: excised animal and human skin, and human stem cell-derived neurons.

Controlled evidence and its limits

The parent hexapeptide has a randomized, placebo-controlled study: 60 Chinese subjects randomized 3:1 to the peptide or placebo for 4 weeks showed lower skin roughness parameters with the peptide and no clear change with placebo (Wang et al., 2013). A 2026 review of peptides in facial plastic surgery notes that most supporting evidence for these peptide classes comes from in vitro and ex vivo work rather than randomized trials (Shomorony and Denton, 2026). No randomized trial of SNAP-8 alone appears in PubMed. Models: human volunteers and literature review.