SNAP-8 (Acetyl Octapeptide-3) is a synthetic octapeptide used in cosmetic formulations as a topical approach to reducing the appearance of expression lines. It is proposed to compete with SNAP-25, a synaptosomal-associated protein central to the SNARE complex, partially attenuating acetylcholine-mediated neuromuscular signalling at the skin surface level. SNAP-8 vs argireline: SNAP-8 is an eight-amino-acid extension of argireline (acetyl hexapeptide-3), which targets the same SNARE-disruption mechanism. The additional residues are proposed to improve binding affinity and prolong the signal-dampening effect, though independent head-to-head data comparing the two peptides in controlled human studies is limited. Both compounds appear in anti-wrinkle cosmetic formulations, often in combination, under the rationale that their slightly different sequences may engage overlapping but distinct binding sites. Clinical evidence for both is modest compared to pharmaceutical-grade botulinum toxin; SNAP-8 is positioned as a lower-potency, non-injectable alternative for formulation use. Cosmetic formulation and concentration: SNAP-8 is used at concentrations of 1–5% in topical cosmetic products, most commonly in eye creams, forehead serums, and expression-line treatments. It is water-soluble and compatible with standard emulsion bases. The compound is sold as a cosmetic ingredient (INCI: Acetyl Octapeptide-3) and is not classified as a drug in most jurisdictions, meaning formulations containing it do not require prescription access. SNAP-8 before and after: Published cosmetic research on SNAP-8 has demonstrated reductions in wrinkle depth measurements of 12–18% over 28-day application periods in some manufacturer-sponsored studies. Independent peer-reviewed data is sparse; results should be interpreted with caution given the source. The mechanism — partial, reversible SNARE interference — suggests any visible effect is transient and dependent on ongoing application, unlike ablative or injectable interventions. Before-and-after photographs from cosmetic trials show modest softening of dynamic expression lines (forehead, lateral canthal area) with consistent daily use. Availability and access: SNAP-8 is available as a cosmetic ingredient through specialty suppliers and is incorporated into commercial skincare products sold without prescription. It is not available in injectable form and has no clinical use outside of cosmetic topical application. Peptide therapy providers indexed on PeptideBase generally do not dispense SNAP-8, as it falls outside the prescription peptide category — it is relevant to consumers researching evidence-backed cosmetic peptides rather than clinical compounding.