Pentapeptide-3
Vialox — the "curare-mimetic" cosmetic peptide (GPRPA). Acts post-synaptically on peripheral nicotinic ACh receptors, unlike the pre-synaptic SNAP-25-mimetic Argireline class. Sometimes marketed as a snake-venom-inspired Botox alternative; efficacy data are primarily from the manufacturer.
A synthetic pentapeptide with the sequence Gly-Pro-Arg-Pro-Ala-NH2 (C21H37N9O5, MW 495.58), originally developed by Pentapharm as Vialox® (later designated Pentapeptide-3V). The sequence is derived from curaremimetic venom peptides and functions as a competitive antagonist at peripheral nicotinic acetylcholine receptors (nAChR) of the neuromuscular junction, producing partial muscle relaxation with no reported action on central neuronal receptors. Manufacturer animal-model data describe an 11 % reduction in skin roughness and 8 % reduction in wrinkle relief after 28 days of twice-daily topical application. Cosmetic ingredient only; no regulated clinical development.
Mechanism of action
Competitive antagonist at peripheral nicotinic acetylcholine receptors (nAChR) on the post-synaptic membrane of skeletal-muscle motor end-plates. By occupying the ACh binding site without triggering ion-channel opening, it blocks depolarisation and reduces the frequency and intensity of muscular contractions. Reported selectivity for peripheral over central (neuronal) nAChRs means central nervous system effects are minimal at topical doses. This post-synaptic mechanism is mechanistically distinct from (and potentially complementary to) the pre-synaptic SNAP-25 competitive-inhibition mechanism of Acetyl Hexapeptide-8 (Argireline) and the enkephalin-receptor mechanism of Leuphasyl. Vialox is classified alongside tubocurarine in the competitive non-depolarising neuromuscular-blocker pharmacologic class, though with vastly lower potency.
Primary uses
- Topical cosmetic anti-aging formulations (expression-line reduction; "topical Botox alternative")
Typical dosing
The concentrations in circulation come from the ingredient's supplier, and a seller's figure is not a source on this site; no study in the sources read sets one.
Regulatory status
Cosmetic ingredient; not a drug. INCI name: Pentapeptide-3 (also marketed as Pentapeptide-3V diacetate).
Status as of this entry's last review, April 19, 2026. Approvals, compounding rules and sport rules change; the regulatory tracker is checked more often.
What we checked
Pentapeptide-3, sold as Vialox, is described as blocking acetylcholine receptors on muscle, a 'topical Botox' claim. On PubMed it appears under that trade name only in two 2026 laboratory and computer-modelling studies, and no human study; this section records what can be checked.
Identity, computed
| Sequence | Gly-Pro-Arg-Pro-Ala-NH2 (GPRPA-NH2) |
| Formula | C21H37N9O5 |
| Average mass | 495.59 g/mol |
| Monoisotopic mass | 495.2918 Da |
| Isoelectric point | none between pH 0 and 14: no acidic group, so the peptide stays positive (net charge +1.98 at pH 7) |
The dataset gives Gly-Pro-Arg-Pro-Ala-NH2, and the calculator agrees with its formula and mass.
Regulatory status, read October 5, 2026
Drugs@FDA: 0 records for “pentapeptide-3”. EMA medicines list: 0 records for “pentapeptide-3”. Run for semaglutide, the same queries return 6 and 5 records (and the registry search 84 trials), so a zero here is an absence, not a broken search. Not named on the WADA 2026 and 2027 Prohibited Lists. As a substance with no current approval for human therapeutic use, it falls under section S0 (non-approved substances), which is prohibited at all times; the lists were read on September 27, 2026.
What the maker or sellers claim
Claim, from the ingredient's maker and cosmetic sellers: It relaxes expression lines by blocking nicotinic acetylcholine receptors. The data come from the maker's material.
About nicotinic receptor blockers
Snake curaremimetic toxins block muscle nicotinic receptors; the 1997 study cited in References describes which toxins bind which receptor types. That is the mechanism the ingredient borrows its name from, not evidence that a cream reaches or blocks those receptors.
What we looked for and did not find
No human study, no registry record and no drug application.
| Source | Query | Results, October 5, 2026 | What it was |
|---|---|---|---|
| PubMed | "pentapeptide-3" Vialox OR GPRPA | 0 | |
| PubMed | Vialox | 2 | two 2026 laboratory and computer-modelling studies |
| ClinicalTrials.gov | pentapeptide-3 | 0 | |
| Drugs@FDA (openFDA) | pentapeptide-3 | 0 | |
| EMA medicines list | pentapeptide-3 | 0 |
References
- [manufacturer] Pentapharm / DSM / dsm-firmenich. "Vialox® (Pentapeptide-3) technical data sheet."
- [pubmed] Servent D, Winckler-Dietrich V, Hu HY, et al. "Only snake curaremimetic toxins with a fifth disulfide bond have high affinity for the neuronal α7 nicotinic receptor." J Biol Chem, 1997;272(39):24279-24286 (curaremimetic selectivity reference). PMID: 9305882.
- [review] Errante F, Ledwoń P, Latajka R, Rovero P, Papini AM. "Cosmeceutical peptides in the framework of sustainable wellness economy." Front Chem, 2020;8:572923. PMID: 33195061.
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This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.