Argireline — acetyl hexapeptide-3 SNARE inhibitor
6-residue peptide that inhibits SNARE complex assembly. Topical anti-wrinkle.
- Class
- Cosmetic peptide (SNAP-25 mimetic; SNARE complex competitive inhibitor)
- Status
- Regulated as a cosmetic ingredient (US FDA cosmetic law; EU CosIng; CIR-assessed). Not approved as a drug for any medical indication. Injection of cosmetic Argireline preparations is not authorized in any jurisdiction in the compiled source.
- Best-supported effect
- Modest reduction in dynamic wrinkle depth (~10–30% from baseline) over 28–60 days of twice-daily topical application at 10% concentration in studied populations; mechanism (competitive SNARE complex inhibition) supported in vitro.
- Main caveat
- Effect size is far below injectable botulinum toxin (50–80% reduction); stratum corneum permeation is the rate-limiting step, not bulk concentration. Most published trials are short (≤2 months) and a meaningful share of the base is manufacturer-associated.
A researcher, an agent, or an algorithm wrote down the sequence and picked a target to hit.
An AI model like OpenFold3 or AlphaFold built a 3D structure and scored how well it fits the binding site.
A second contributor repeated the computation on their own hardware and the scores matched.
Reference scaffold compound — documented synthesis
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Reference scaffold — used as positive control in bioassays; activity well established
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Snapshot
Class: Cosmetic peptide (SNAP-25 mimetic; SNARE complex competitive inhibitor)
Evidence tier: Human clinical evidence
Status: Regulated as a cosmetic ingredient (US FDA cosmetic law; EU CosIng; CIR-assessed). Not approved as a drug for any medical indication. Injection of cosmetic preparations is unauthorized and has caused infection.
Best-supported effect: Modest reduction in dynamic wrinkle depth (roughly 10–30% from baseline) over 28–60 days of twice-daily topical application at 10% concentration in studied populations; mechanism (competitive SNARE inhibition) supported in vitro.
Main caveat: Effect size is far below injectable botulinum toxin (50–80% reduction). Stratum corneum permeation is the rate-limiting step, not bulk concentration. Most published trials are short (≤2 months) and many are manufacturer-associated rather than independent head-to-head comparisons.
What this is
Argireline is a synthetic acetylated hexapeptide (Ac-EEMQRR-NH₂) that mimics the N-terminal sequence of SNAP-25, one of the three SNARE proteins that drive synaptic vesicle fusion at the neuromuscular junction. By competing with native SNAP-25 for incorporation into the SNARE complex, it partially and reversibly reduces acetylcholine release, softening the muscle contractions that produce dynamic expression lines.
The peptide was developed by Lipotec S.A. (Barcelona) and trademarked in 2001. It is now produced by multiple manufacturers, listed under the INCI names acetyl hexapeptide-3 and acetyl hexapeptide-8, and appears in hundreds of over-the-counter serums and creams marketed for forehead, glabella, and crow's-feet lines. It is one of the most widely used cosmetic peptides globally and is regulated as a cosmetic ingredient — not as a drug.
The card describes Argireline as studied: a topical cosmetic active with a real, modest, reproducible wrinkle-depth effect. It is not a substitute for injectable botulinum toxin, and the cosmetic preparations are not authorized for injection.
Evidence map
| Evidence layer | Grade | What it supports |
|---|---|---|
| Human | Moderate (topical only) | Multiple clinical studies, including randomized placebo-controlled trials, reporting roughly 17–30% wrinkle-depth reduction over 28–60 days at 10% topical concentration. Long-term (>2–3 month) data are not present. |
| Animal | Not individually extracted | Research mechanistic and SNARE-related work but does not list dedicated animal efficacy studies. |
| In vitro | Strong (mechanism and assay context) | Competitive SNARE complex inhibition is well-demonstrated in cell-free and cellular assays; permeation studies confirm only a small fraction crosses the stratum corneum. |
| Computational | None identified | No structure prediction or docking data attached. |
| Mechanism | Strong | SNARE-complex biology and acetylcholine release at the neuromuscular junction are well-characterized; Argireline's competitive, reversible inhibition is plausible and consistent with the in vitro data. |
The strongest results come from short topical studies. Several published trials are manufacturer-associated, and rigorous independently funded head-to-head comparison against botulinum toxin is not present in the available literature.
Claim check
| Claim | Verdict | Evidence layer | Confidence |
|---|---|---|---|
| Reduces dynamic wrinkle depth with regular topical application | Supported (topical RCTs, 10% concentration, 28–60 days) | Human clinical | Medium — short-duration trials; effect size 10–30% vs. baseline |
| Equivalent to or substitute for botulinum toxin injection ("topical Botox") | Contradicted / not established | Human clinical and mechanistic | High — Argireline produces ~10–30% reduction over weeks; botulinum toxin produces 50–80% reduction within days |
| Higher cosmetic concentrations (above ~10%) produce proportionally greater clinical effect | Weak / not established | Human clinical and in vitro permeation | Medium — stratum corneum permeation, not bulk concentration, is rate-limiting; no source-attached dose-response data above 10% |
| Safe to inject cosmetic Argireline preparations for stronger effect | Contradicted | Human (case report) and regulatory | High — case report of Mycobacterium abscessus facial infection after unlicensed injection; cosmetic products are not sterile injectables |
| Prevents long-term development of expression lines when started in younger users | Not established | Human | Low — no prospective long-term preventative trial in the available literature |
| Produces immediate visible effect on first application | Contradicted | Human clinical | Medium — measurable wrinkle-depth reduction emerges over 14–28 days; immediate "tightening" reflects film-forming polymers and humectants in the vehicle, not SNARE inhibition |
Human exposure studied
This section reports exposure used in topical clinical studies of Argireline. It is not a personalized protocol and does not establish injectable use.
| Context | Population | Exposure studied | Duration | Endpoint | Limitation |
|---|---|---|---|---|---|
| Clinical / RCT (topical) | Adult subjects with dynamic facial expression lines, including a Chinese-subject randomized placebo-controlled study | 10% topical Argireline applied to expression-line areas; trial protocols typically used twice-daily application | 28 days to ~2 months | Wrinkle-depth reduction (instrumented and clinical scoring) | Short trial windows; manufacturer-associated work is overrepresented in the published base; permeation across stratum corneum is the rate-limiting step |
| Clinical (combination) | Adult subjects (RCT of tripeptide-10-citrulline + acetyl hexapeptide-3) | Combination topical formulation | Trial duration not individually extracted | Wrinkle and skin-surface endpoints | Combination design — does not isolate Argireline effect |
| Pilot clinical (off-cosmetic indication) | Patients receiving botulinum toxin therapy for blepharospasm | Topical acetyl hexapeptide-8, adjunct to ongoing botulinum toxin therapy | Pilot study; details not individually extracted | Blepharospasm-related endpoints | Small pilot; adjunct context, not a standalone efficacy trial |
| In vitro permeation | Human skin / model membranes | Topical formulation; emulsion and vehicle variants | Single-application permeation timepoints | Fraction of peptide crossing stratum corneum into viable epidermis | Permeation models are surrogates; only a small fraction of applied peptide crosses, and a smaller fraction reaches facial musculature depth |
Exact regimens used in individual trials are not separately extracted into this card; published work generally clusters around 10% concentration and 28–60 day twice-daily application.
Safety signals
| Signal | Evidence context | Notes |
|---|---|---|
| Mild skin irritation | Topical cosmetic use | Reported as rare; topical Argireline is described as very well tolerated in the available literature |
| Contact dermatitis / hypersensitivity | Topical cosmetic use | Rare but reported; may relate to vehicle excipients (fragrance, preservatives, emulsifiers) as well as the peptide itself |
| Increased irritation / absorption on compromised skin | Topical use on broken or inflamed skin | available literature describes broken/inflamed skin as a contraindication for application |
| Mycobacterial infection (Mycobacterium abscessus) after facial injection | Case report | Tied specifically to unlicensed injection of cosmetic Argireline preparation, which is not a sterile injectable product. Not a topical-use signal. |
| Long-term topical safety beyond ~2–3 months | Not established | Long-term human safety data for daily topical use over years is not present, the long-term profile as "favorable based on extensive cosmetic use" but no formal long-term study is attached |
Source-described cautions for topical use: application is intended for intact skin only; effects require continued application; results are more modest than injectable treatments. The available literature lists pregnancy, breastfeeding, and pediatric use as contexts without dedicated safety data and recommends conservative caution.
Interaction signals: documented systemic drug interactions for topical cosmetic Argireline are minimal. The available literature describes co-formulation with other topical actives (niacinamide, hyaluronic acid, ceramides, matrikine peptides such as the matrixyl family) as common; head-to-head evidence that combinations outperform single-peptide products is limited. No documented concern was extracted for combining topical Argireline with oral medications, systemic hormones, or antiplatelet/anticoagulant therapy at typical cosmetic exposure.
Regulatory status
| Region / body | Status | Notes |
|---|---|---|
| US (FDA) | Cosmetic ingredient | Regulated under FDA cosmetic law, not as a drug. Over-the-counter sale in finished cosmetic formulations is permitted without prescription. Not approved for treatment of wrinkles, blepharospasm, or any medical condition. Cosmetic claims on labels are limited to appearance language. Injection of cosmetic Argireline preparations is not authorized. |
| EU | Cosmetic ingredient | Acetyl hexapeptide-8 is included in the EU Cosmetic Ingredient Database (CosIng) and is broadly permitted in cosmetic formulations. |
| Canada / UK / Australia / Japan | Cosmetic ingredient | available literature describes broad permitted cosmetic-ingredient use across these markets. |
| CIR (Cosmetic Ingredient Review) | Assessed safe | CIR has assessed acetyl hexapeptide-8 as safe for cosmetic use at typical formulation levels. |
| WADA | Not prohibited | Argireline is not listed on the WADA Prohibited List. Topical cosmetic use has no realistic systemic performance relevance. |
| Injectable use | Not authorized in any jurisdiction in the available literature | No authorized injectable Argireline product exists; cosmetic preparations are not sterile injectables. |
Clinical trials
Research several published clinical and randomized controlled trials of topical Argireline (acetyl hexapeptide-3 / hexapeptide-8) for wrinkle-related endpoints, plus one pilot in blepharospasm patients receiving botulinum toxin therapy. Individual NCT or registry IDs are not present.
| Trial / source | Phase / type | Population | Endpoint | Status / result |
|---|---|---|---|---|
| Anti-wrinkle efficacy in Chinese subjects, randomized placebo-controlled | Randomized controlled trial | Chinese adult subjects with facial expression lines | Wrinkle-depth reduction at studied timepoints | Published; reported wrinkle-depth reduction at 10% topical use |
| Synthetic hexapeptide (Argireline) anti-wrinkle activity | Clinical trial | Adult subjects with facial expression lines | Wrinkle-depth reduction | Published |
| Combination of tripeptide-10-citrulline and acetyl hexapeptide-3 | Prospective, randomized controlled trial | Adult subjects | Combination skin/wrinkle endpoints | Published; combination design — does not isolate Argireline effect |
| Topical acetyl hexapeptide-8 pilot in blepharospasm patients on botulinum toxin therapy | Randomized controlled pilot | Patients receiving botulinum toxin for blepharospasm | Blepharospasm-related endpoints | Published pilot |
| Argireline in serum with hyaluronic acids, Visia analysis | Clinical / instrumented analysis | Adult subjects | Skin-surface wrinkle endpoints by Visia camera | Published |
| Anti-wrinkle efficacy in Chinese subjects | Clinical efficacy study | Chinese adult subjects | Wrinkle endpoints | Published |
| Anti-wrinkle efficacy of Argireline | Clinical efficacy study | Adult subjects | Wrinkle endpoints | Published |
Additional trial-level details (enrollment, exact regimen, completion dates) are not individually extracted. Review and preclinical articles in the reference list are not included as trial rows.
Mechanism
Argireline (Ac-EEMQRR-NH₂) is a six-residue acetylated, C-terminal-amidated peptide whose sequence reproduces the N-terminus of SNAP-25, one of three SNARE proteins (with syntaxin-1 and VAMP-2) that assemble to drive synaptic vesicle fusion at the neuromuscular junction.
By competing with native SNAP-25 for incorporation into the SNARE complex, Argireline partially blocks SNARE assembly. The downstream consequence is reduced acetylcholine release from motor-neuron terminals, decreased force of facial muscle contraction, and softening of the dynamic wrinkles that repeated expressions produce. Unlike botulinum toxin, which enzymatically cleaves SNARE proteins and produces a long-lasting paralytic effect, Argireline's competitive inhibition is reversible and dose-dependent — the inhibition is active only while the peptide is present at the junction.
The dominant clinical limitation is delivery, not target engagement. Argireline has a molecular weight of roughly 888 Da and is hydrophilic with multiple charged residues — physicochemical properties that, on paper, predict poor transdermal permeation. In vitro permeation studies in the available literature confirm that only a small fraction of applied peptide crosses the stratum corneum into viable epidermis, and an even smaller fraction reaches the depth of facial musculature where neuromuscular junctions actually sit. This is the central mechanistic reason in vivo effect sizes are modest relative to the in vitro target potency.
Mechanism limitations:
- The target (presynaptic SNARE complex at the neuromuscular junction) is largely inaccessible from the skin surface.
- Formulation strongly affects delivery (liposomal encapsulation, penetration enhancers, microneedle delivery, occlusive vehicles).
- Mechanism does not upgrade clinical confidence: in vitro SNARE inhibition is well-demonstrated, but it does not by itself establish how much of that activity is realized at the human neuromuscular junction under topical use.
Chemistry
| Field | Value |
|---|---|
| Amino-acid sequence | EEMQRR (Glu-Glu-Met-Gln-Arg-Arg) |
| Sequence with modifications | Ac-EEMQRR-NH₂ |
| Length | 6 amino acids |
| Topology | Linear |
| N-terminal modification | Acetylation |
| C-terminal modification | Amidation |
| Approximate molecular weight | ~888 Da (as described in the available literature) |
| INCI names | Acetyl hexapeptide-3; Acetyl hexapeptide-8 |
| Origin | Synthetic biomimetic of the SNAP-25 N-terminus |
| Sequence confidence | Verified against the available literature |
The naming change from acetyl hexapeptide-3 to acetyl hexapeptide-8 is an INCI nomenclature update, not a sequence change. Salt form and CAS identifier are not individually extracted.
Open questions
- Independent head-to-head trials vs. botulinum toxin: Most published comparative framing is implicit (marketing) rather than head-to-head against the active comparator. Rigorous independently funded comparative trials are absent.
- Long-term topical safety and efficacy: Daily use over years is common in practice but has not been studied as a distinct efficacy or safety question. Trials beyond 2–3 months are not present in the available literature.
- Real-world skin-penetration across commercial formulations: "Contains Argireline" does not guarantee equivalent delivery; the effective concentration reaching neuromuscular junctions in everyday use is poorly characterized.
- Dose-response above 10%: Whether higher concentrations yield additional clinical benefit, or merely higher surface concentration, is not well established.
- Preventative use in younger users: Whether starting Argireline in the 20s or 30s alters the trajectory of expression-line development over decades has not been tested prospectively.
- Responder vs. non-responder phenotypes: Clinical response is variable; the biological basis (skin thickness, muscle mass, genetic factors) is not characterized.
- Independence of evidence base: A meaningful share of published work is manufacturer-associated. Independent replication depth is a limitation.
▸3-letter notation
▸citationbibtex
@peptide{pep00014,
sequence = {EEMQRR},
target = {cosmeceutical},
author = {peptidemodel},
year = {2026},
status = {bioassayed}
}