compound
Acetyl hexapeptide-8
The peptide behind the botox-in-a-cream category, read from primary records: what a US Food and Drug Administration laboratory measured in every layer of human skin, what two National Institutes of Health trials posted, and what the cosmetics industry's own safety panel concluded in 2025.
- Primary sources Registry records and papers are read at the source, not through summaries. Read the methodology
- Every claim graded Each claim about what a compound does carries an evidence tier and a numbered citation. How grades derive
- Sells nothing No cart, no price, and no product page anywhere on this site. Conflict disclosure
- Corrections logged Errors are fixed and recorded in a permanent public log, never edited away. Corrections log
Acetyl hexapeptide-8 is the most searched cosmetic peptide there is, and it is one of the few compounds on this site that is lawfully sold. It is a listed cosmetic ingredient with an INCI name, which puts it inside cosmetics law rather than outside drug law, and a company may advertise how it makes skin look without proving that it does anything.
The claim it is sold on is specific and testable: that it gets in the way of the protein complex a nerve ending assembles to signal a muscle, the same machinery an injected botulinum toxin acts on. Reaching that machinery means crossing the outer layer of skin, then the rest of the epidermis, then the dermis.
Three primary records decide how to read that claim, and none of them appears on the pages that rank for this ingredient. An FDA laboratory applied the peptide at 10 per cent and measured every layer of human skin. The National Institute of Neurological Disorders and Stroke tested the mechanism twice at a clinical endpoint and posted both sets of results. And the cosmetics industry's own expert panel published a safety conclusion in 2025 with a number attached to it. This page is built out of those three, and the efficacy literature is read beside them rather than on its own.
| Property | Value | Source |
|---|---|---|
| Category | Listed cosmetic ingredient, lawfully sold and lawfully advertised on appearance, sold as a topical alternative to an injected muscle relaxant | PMID 40196949 |
| Also known as | Argireline, and formerly acetyl hexapeptide-3 under the older nomenclature. Both names remain on labels for the same ingredient | The naming traps in full |
| Registered human trials | Six. Four test the peptide on its own and two carry it as one ingredient in a multi-ingredient product. Two of the four have posted results | ClinicalTrials.gov, read 23 August 2026 |
| How far it gets into skin | An FDA laboratory applied it at 10 per cent to human skin for 24 hours and found 0.22 per cent of the dose in the outer layer, 0.01 per cent in the epidermis, and none in the dermis | PMID 24754410 |
| Industry safety panel conclusion | Safe in cosmetics at concentrations up to 0.005 per cent, and the panel states the available data are insufficient to make that determination above 0.005 per cent | PMID 40673537, published 2025 |
| Approval status | Not an approved drug in any indication. It does not need to be: a cosmetic ingredient carries no pre-market approval and no efficacy requirement | 21 USC 321 |
Not medical advice
This page reports what has been documented about a compound. It is not medical advice, not a diagnosis, not a dosing protocol, and not a recommendation to obtain or use anything described here. Talk to a licensed clinician about anything concerning your health. Read the full disclaimer.
Reviewed against editorial standards Updated
Key takeaways
- A US Food and Drug Administration laboratory applied an oil-in-water emulsion containing 10 per cent of the peptide to human cadaver skin, left it 24 hours, then measured each layer by mass spectrometry against isotope-labelled standards. Most of it washed off the surface. Of the applied dose, 0.22 per cent stayed in the outer layer and 0.01 per cent reached the epidermis. None was detected in the dermis or in the fluid beneath the skin. [In-vitro] [6]
- The Expert Panel for Cosmetic Ingredient Safety published a conclusion of safety in cosmetics in 2025, bounded at concentrations up to 0.005 per cent, and stated that the available data are insufficient to reach that conclusion at higher concentrations. That second half describes the data rather than reporting harm.
- The mechanism has been tested at a clinical endpoint twice, by the National Institute of Neurological Disorders and Stroke, in involuntary eyelid closure. The first trial randomised 24 patients and posted a primary result its own published abstract calls a trend rather than a difference: 3.71 months against 3.03 months. [Human RCT] [5]
- The second of those two trials raised the concentration ten-fold, enrolled eight participants across three arms, is recorded as terminated with no reason stated, and was never published. Its results exist only in the registry.
- The most-cited efficacy result is one randomised placebo-controlled trial in 60 subjects with three to one allocation over four weeks, which puts roughly 15 people on placebo. It reported a total anti-wrinkle response of 48.9 per cent against 0 per cent on placebo by subjective assessment, and decreased roughness parameters on silicone replicas at p below 0.01. The same trial and the same figure appear in two journals in the same year. [Human RCT] [2] [3]
- The one study that isolates the peptide against its own vehicle delivered it through a microneedle patch that punctures the outer layer of skin. It found a difference. What it tests is the ingredient with the barrier bypassed, which is a different question from the ingredient in a cream. [Human RCT] [9]
- REGISTERED HUMAN TRIALS
- 6
- OF THE APPLIED DOSE DETECTED IN THE DERMIS
- None
- NUMBERED SOURCES
- 24
- EVIDENCE GRADE
- B
Who researches Acetyl hexapeptide-8?
Two readers arrive here and the record answers them differently.
The first is comparing this ingredient with an injected muscle relaxant, usually after meeting the comparison in an advertisement. The useful part of the record for that reader is not the wrinkle trial. It is the pair of trials that tested the mechanism where it can be measured objectively, and the FDA measurement of how much of the peptide arrives.
The second is choosing between this ingredient and the eight amino acid version sold as the stronger one. That comparison has its own page, and the short answer is that no published study ranks them.
What is Acetyl hexapeptide-8?
Plain-English version: a six amino acid peptide copied from one end of a protein that nerve endings use to release their signal, formulated into a cream or a serum.
A nerve ending releases its signal by assembling a protein complex called SNARE, which pulls a vesicle full of signalling chemical against the cell membrane so it can empty. One of the three proteins in that complex is SNAP-25. This peptide copies six amino acids from one end of SNAP-25, and the proposal is that the copy competes with the real thing and slows the assembly down.
An injected botulinum toxin interferes with the same complex, by cutting SNAP-25 rather than competing with it, and it is delivered into the muscle rather than onto the skin above it. The founding 2002 paper describes the peptide as inhibiting neurotransmitter release with a potency it calls similar to that toxin while noting much lower efficacy [1]. Those are measurements in a laboratory preparation, not in a person, and the difference between the two matters more here than anywhere else on this site.
The molecule is water-loving and, for a skin-penetration problem, large. Both properties work against it: the outer layer of skin is a lipid barrier built to keep water-soluble molecules out. That is the physical fact underneath every efficacy question on this page, and it has been measured directly rather than argued about [6] [8] [12].
The trailing number is a nomenclature artefact. The ingredient was listed as acetyl hexapeptide-3, the listing was revised, and it is now acetyl hexapeptide-8. Both names remain in circulation for the same molecule.
Ac-Glu-Glu-Met-Gln-Arg-Arg-NH2, written Ac-EEMQRR-NH2 · Not stated here. No primary chemical reference was read for this page, and the sequence below is the identity this page relies on
How strong is the evidence, claim by claim?
Every claim area this compound is discussed for gets a row, including the ones with the weakest support. The tier records what the row rests on, and the last column states what that work can and cannot show. Each tier links to its definition on the methodology page.
| Evidence Area | What Has Been Studied | Evidence Level | What It Can and Cannot Show |
|---|---|---|---|
| Appearance of periorbital expression lines from a topical formulation | The claim the ingredient is sold for. A randomised, placebo-controlled trial in 60 Chinese subjects with periorbital wrinkles, allocated three to one in favour of the active arm, applied twice daily for four weeks. Subjective global assessment reported a total anti-wrinkle response of 48.9 per cent against 0 per cent on placebo, and silicone replicas read by a wrinkle-analysis instrument showed decreased roughness parameters at p below 0.01, with no significant change on placebo [2] [3] | [Human RCT] | Three to one allocation puts roughly 15 people on placebo, and the study ran four weeks. The headline figure comes from subjective global assessment rather than the instrument. The same 60-subject study and the same 48.9 per cent figure appear in two journals in the same year, so a reader counting papers counts one trial more than once. A separate registered Phase 3 of 70 participants completed in 2009 has posted no results and no publication was found for it |
| Wrinkle measures when the peptide is delivered through a microneedle patch | The only study found that isolates this peptide against its own vehicle. Fifty-two Korean women in a double-blind, randomised, controlled, split-face trial with three arms: a cross-linked hyaluronic acid microneedle patch alone, the same patch carrying this peptide, and the same patch carrying epidermal growth factor. Both active arms showed greater wrinkle improvement than the patch alone at p below 0.05 over 29 days [9] | [Human RCT] | A microneedle patch punctures the outer layer of skin, which is the barrier every permeability question about this ingredient concerns. The design answers what the peptide does once it is past that barrier, and says nothing about a cream that has to cross it. This is not the marketed route |
| Involuntary eyelid closure, where the marketed mechanism was tested against a measurable clinical endpoint | Two randomised, placebo-controlled trials run by the National Institute of Neurological Disorders and Stroke, both with results posted to the registry. The first enrolled 24 patients at 0.005 per cent and measured how long a rating scale took to return to baseline after a botulinum toxin injection given at the same time. The second raised the concentration to 0.05 and 0.025 per cent and enrolled 8 participants across three arms [5] [17] [18] | [Human RCT] | The published abstract of the first calls its primary result a trend, at 3.71 months against 3.03 months, and no statistical analysis is posted for any outcome in either trial. The second is recorded as terminated with no reason given in the registry and no publication was found. Eight participants across three arms cannot settle anything, and the numbers below are reported as posted with their arm sizes beside them. Two of the six authors of the published trial state an affiliation with the company that supplies the peptide |
| Whether the peptide reaches below the epidermis from a topical formulation | A US Food and Drug Administration laboratory applied an oil-in-water emulsion containing 10 per cent of the peptide to human cadaver skin and hairless guinea pig skin at 2 mg per square centimetre for 24 hours, then tape-stripped the layers, heat-separated epidermis from dermis, and measured each fraction by mass spectrometry against stable isotope-labelled internal standards. Of the applied dose, 0.22 per cent was found in the outer layer of human skin, 0.01 per cent in the epidermis, and none in the dermis or the fluid beneath [6] [8] [10] [12] | [In-vitro] | Excised skin in a diffusion cell is not living skin, and a 24 hour exposure is not repeated daily use. What the design does establish is a measurement rather than an argument, at a concentration far above what a finished product carries. Formulation work shows the number can be moved: a multiple water-in-oil-in-water emulsion increases delivery into porcine skin over simple emulsions, and chemical modification to reduce the peptide's charge improves permeation in vitro. A 2025 review of this ingredient concludes that low skin penetration limits its bioavailability and that whether it reaches neuromuscular junctions remains uncertain |
| Interference with the SNARE complex and with neurotransmitter release | The mechanism the ingredient is sold on. The 2002 paper that named it reports that the peptide inhibited neurotransmitter release with a potency it describes as similar to botulinum toxin A while noting much lower efficacy, and attributes that to interference with the formation or stability of the SNARE complex. A 2018 study measured inhibition of glutamate release from neurons derived from human dental pulp stem cells across four analogues of the peptide [1] [11] | [In-vitro] | Both are cell and preparation measurements. Neither establishes that the effect occurs in a person, and the penetration row above is the reason that gap is not a technicality: the complex this mechanism acts on sits below the layer the peptide was last detected in. Every author of the 2002 paper worked at a university department or the supplying company, and the paper reports its volunteer skin-topography result without a placebo arm, a randomisation, or a participant count in the abstract |
| Effects on dividing cells in culture | An independent laboratory measured anti-proliferative effects of a solution of the peptide on human embryonic kidney cells, human neuroblastoma cells and primary skin fibroblasts, using a formazan-based assay, and calculated the concentration that halves proliferation for each. The stated reason for running it was that the available toxicity data came from the manufacturer [13] | [In-vitro] | The effect was dose dependent and appeared at concentrations 18 to 10,000 times higher than the reference compound doxorubicin required, depending on the cell line. That is a large margin, and cells in a dish are not skin. The measurement is recorded here because it is the only independent cytotoxicity work found, not because it establishes a risk |
| Infection following injection of the ingredient, which is not how it is sold or labelled | A single published case report. A 45-year-old woman received injections of the ingredient into the forehead and temples and developed redness, nodules and abscesses at the injection sites within a week. Culture of the pus grew Mycobacterium abscessus, and the lesions resolved over five months of clarithromycin and moxifloxacin [14] | [Anecdote] | One case, and the report is about an injection procedure rather than about the molecule. This is a cosmetic ingredient formulated for application to the surface of skin. The report is on this page because the practice exists and a reader searching this ingredient should meet it |
Rolled up, that puts Acetyl hexapeptide-8 at evidence grade B Human data, not settled . Human evidence for the marketed use has read out, and it has not settled the question: the record here does not clear the bar grade A sets, which is two phase-3-scale randomized trials of the marketed use, each cited and each stating whether it met its primary endpoint, agreeing with each other. A grade describes the quality of the research, not whether something works and not whether anyone should use it. The derivation is published.
How Acetyl hexapeptide-8 is thought to work
The mechanism story for this ingredient is unusually easy to state and unusually easy to test, which is why the record below is worth reading in order rather than as a headline.
1. What the peptide is a copy of, six amino acids taken from one end of a protein that nerve endings use to release their signal (established as the design origin)
A nerve ending signals a muscle by emptying a vesicle of chemical into the gap between them. Emptying it requires the SNARE complex, three proteins that zip together and pull the vesicle against the membrane. SNAP-25 is one of the three.
This peptide is a copy of six amino acids from one end of SNAP-25. The design idea is competition: a fragment that looks like part of the real protein occupies the place the real protein would take, and the complex assembles more slowly. The 2002 paper reports that inhibition in a laboratory preparation and describes the potency as similar to botulinum toxin A with much lower efficacy.
Two words in that sentence carry the whole comparison people arrive here for. Potency is the concentration at which something acts. Efficacy is how much it does at any concentration. A molecule can act at a similar concentration and still do far less. [In-vitro] [1]
2. The step the mechanism needs and the measurement of it, reaching a nerve ending means getting through skin, and an FDA laboratory measured how far it got (measured in excised human skin)
A neuromuscular junction sits below the dermis. Between it and a cream are the stratum corneum, the rest of the epidermis, and the dermis. Every claim about this ingredient acting on a nerve ending requires the molecule to make that trip.
The Food and Drug Administration's own laboratory measured it. An oil-in-water emulsion at 10 per cent, applied to human cadaver skin at 2 mg per square centimetre for 24 hours, then washed, tape-stripped layer by layer, and read by mass spectrometry against isotope-labelled internal standards. The majority washed off the surface. In human skin, 0.22 per cent of the applied dose was in the outer layer and 0.01 per cent in the epidermis. In the dermis and in the fluid collected beneath the skin, none was detected. Hairless guinea pig skin gave the same picture at 0.54 and 0.01 per cent.
That measurement was made at 10 per cent, which is far above what a finished product carries, and it still returned nothing below the epidermis. The number is not fixed: formulation changes move it, and a multiple water-in-oil-in-water emulsion delivers more into porcine skin than a simple emulsion does. A 2025 review of this ingredient states the position in its own words, that low skin penetration limits bioavailability and that whether the peptide reaches neuromuscular junctions remains uncertain. A 2022 review reaches the same conclusion for anti-wrinkle peptides as a class. [In-vitro] [6] [8] [10] [12]
3. Where the mechanism was tested against something measurable, the National Institutes of Health tried it on a condition where muscle weakening can be scored (two randomised trials, both with posted results)
Blepharospasm is involuntary forced closure of the eyelids. Clinicians manage it by injecting botulinum toxin to weaken the muscle, and its severity is scored on published rating scales. That makes it the one place a topical claiming the same mechanism can be tested against a number rather than against an appearance.
The National Institute of Neurological Disorders and Stroke ran that test twice, and the eyelid is the thinnest skin on the body, which gives the peptide the shortest trip it will ever have. Both sets of results are posted. The section below reports them. [Human RCT] [5] [17] [18]
What we do not know
Whether the peptide reaches a neuromuscular junction in living human skin at any concentration. The 2025 review of this ingredient states this as unresolved, and the FDA measurement found none below the epidermis in excised skin.
Whether the 0.005 per cent figure in the 2025 industry safety conclusion and the 10 per cent figures in the founding paper and the FDA study are stated on the same basis. This site has not read the full panel report and does not put a multiplier on the two.
Why the second blepharospasm trial was terminated. The registry's field for that reason is empty, and nothing else on the record states one.
Whether the two 2013 papers reporting a 48.9 per cent anti-wrinkle response describe the same 60 participants. The abstracts report the same design, the same figure and overlapping author lists, and the full texts were not obtained.
What the registered Phase 3 of 70 participants found. It completed in 2009, posted no results, and no publication was located for it.
What this evidence can and cannot show
These results come from Cell and tissue preparations for the target work, excised human and animal skin for the delivery work, and human participants for the clinical trials. in Neurotransmitter release assays, human dental pulp stem cell derived neurons, Franz diffusion cells with human cadaver and porcine skin, and randomised trials in wrinkles and in blepharospasm., not from people. An animal model is a deliberate simplification: the injury is created on purpose, the animal is young and healthy, the dose is scaled to body weight in a way that does not translate directly, and the outcome is measured at a fixed point rather than lived with. Cell and tissue work is a further step removed, because the concentrations that produce an effect in a dish are often far above anything a body reaches. Mechanism is a reason to run a trial. It is not a substitute for one, and compounds that looked mechanistically convincing have failed in people many times.
Has Acetyl hexapeptide-8 been tested in humans?
Six completed human studies exist and they answer four different questions, which is why the record looks larger than it is when the studies are counted and smaller than it is when only the wrinkle literature is read.
Two of the six posted their results to the registry and are reported here from those posted results, field by field. Two completed and posted nothing at all.
| Study | People | What was done | Result | Evidence level |
|---|---|---|---|---|
| Periorbital wrinkles, 60 subjects | 60, allocated 3 to 1 | Randomised, placebo-controlled, four weeks, twice daily. Total anti-wrinkle response 48.9 per cent against 0 per cent on placebo by subjective assessment, and decreased roughness parameters on silicone replicas at p below 0.01 | The most-cited efficacy result. Roughly 15 people on placebo. Reported in two journals in the same year with the same figure | [Human RCT] |
| Blepharospasm, first trial (NCT00942851) | 24, twelve per arm | Randomised, triple-masked, placebo-controlled, peptide at 0.005 per cent. Primary outcome time until the rating scale returned to baseline: 3.71 months active against 3.03 months placebo. Disability scale change at three months: 30.89 per cent active against 32.32 per cent placebo | Results posted. The published abstract calls the primary result a trend. No statistical analysis is posted for any outcome | [Human RCT] |
| Blepharospasm, second trial (NCT01750346) | 8, across three arms of 3, 2 and 3 | Randomised, double-masked, at 0.05 and 0.025 per cent, run because the registry records that the concentration used first was not very effective. Primary rating scale at two months, where a higher score is worse: 6 and 7 in the two active arms against 4.33 on placebo | Results posted, never published. Recorded as terminated with no reason stated. One withdrawal for an adverse event in the highest-concentration arm | [Human RCT] |
| Periorbital wrinkles, Phase 3 (NCT01381484) | 70 | Randomised, triple-masked, a 10 per cent gel applied twice daily, primary outcome at three months, completed 2009 at a university in Thailand with a commercial collaborator | No results posted and no publication located. The largest registered trial of this ingredient and nothing is known about what it found | [Human RCT] |
| Cosmetic appearance of oily skin (NCT02597777) | 14 | Randomised, quadruple-masked, peptide at 10 per cent in a lotion base against the same base, physician-graded shine at four weeks, completed 2016 at a university in California | No results posted and no publication located. Not a use the ingredient is marketed for | [Human RCT] |
| Microneedle patch, split-face (PMID 33911590) | 52, 50 completing | Double-blind, randomised, controlled, split-face, three arms. The patch carrying this peptide beat the patch alone on wrinkle measures at p below 0.05 over 29 days | The only design found that isolates the peptide against its own vehicle. Delivery is through microneedles that puncture the skin barrier | [Human RCT] |
| Multi-ingredient products (NCT03878381, NCT06143033) | 10 and 35 | A compounded cream listing twelve actives, and a single-arm eye serum with twenty-four ingredients and no control | Neither is evidence about this ingredient. Both are listed so the registry count on this page can be checked against the registry | [Anecdote] |
Why we are not calling this proof
A trial of a product is not a trial of an ingredient. Two of the six registered records carry this peptide inside a formulation with a dozen or more other actives, and nothing in either can be attributed to it.
A registered trial that completed and posted nothing has told the record only that it happened. Two of the six are in that position, including the largest one, and neither counts as evidence in either direction.
The two blepharospasm trials are reported here at their posted values with their arm sizes attached. Twenty-four participants and eight participants are small, no statistical analysis is posted for either, and neither result establishes that the peptide does or does not work.
Benefits: what the research shows
The matrix above holds each claim and what sits behind it. This section is about the shape of the record as a whole, which is the part a reader cannot get from a row.
The honest bottom line on benefits
The efficacy literature and the delivery literature disagree, and both are real. One randomised trial reported a measured reduction in roughness parameters on a wrinkle-analysis instrument. An FDA laboratory measuring the same molecule at twenty times the concentration in the strongest NIH trial found none of it below the epidermis.
Those two are only in conflict if the mechanism story is required to be true. A change in a roughness parameter can come from something other than a nerve ending: a peptide that stays in the outer layer of skin sits in a hydrated film, and hydration changes how a surface reads to an instrument. The literature does not settle which explanation applies, and this site is not going to pick one.
What the record does establish is narrower and more useful. The mechanism the ingredient is sold on has been tested twice at a clinical endpoint by a national institute, on the thinnest skin on the body, with both results posted, and neither trial was published as a positive result. Anyone citing this ingredient's evidence base without those two trials is citing half of it.
How long Acetyl hexapeptide-8 stays in the body
There is no absorption figure for a person, no half-life, and no exposure measurement, because the studies that would produce them have not been run. For a topical cosmetic that is ordinary rather than surprising: nothing requires them.
What stands in their place is diffusion-cell work. Applied at 10 per cent to human cadaver skin, 0.22 per cent of the dose was recovered from the stratum corneum and 0.01 per cent from the epidermis, with none in the dermis or the receptor fluid, and no breakdown product of the peptide detected anywhere. Emulsion type changes the amount delivered into skin, with water-rich formulations outperforming an oil-rich one.
Those numbers describe how much of an applied dose stays in the skin's outer layers over 24 hours. They do not describe what a person absorbs over months of daily use, and nothing on the record does.
No human pharmacokinetic study of this ingredient was found. What exists is delivery measurement in excised skin. [In-vitro] [6] [10]
What is documented about dosing
Nothing here is a use instruction. Concentrations are reported as what a study used or what a panel concluded about available data.
Commonly cited protocols (extrapolated, not validated)
Nothing here is a dosing recommendation. Statements about dosing reflect community and research reports only.
| Study | What was given | Frequency | Duration | Notes |
|---|---|---|---|---|
| Founding 2002 study | 10 per cent of the peptide in an oil-in-water emulsion | Twice daily | 30 days | Skin topography in healthy women volunteers, no placebo arm reported in the abstract |
| FDA penetration study | 10 per cent in an oil-in-water emulsion | Single application | 24 hours | Excised human and hairless guinea pig skin, not a person |
| First blepharospasm trial | 0.005 per cent | Twice daily to the eyelids | 3 to 7 months of follow-up | Randomised against an identical cream without the peptide |
| Second blepharospasm trial | 0.05 per cent and 0.025 per cent | As described in the registry record | Up to 7 months of follow-up | Terminated with no reason stated, results posted |
| Registered Phase 3 | A 10 per cent gel | Twice daily | 3 months | No results posted |
| 2025 industry safety conclusion | Up to 0.005 per cent | Not applicable | Not applicable | The panel states the available data are insufficient to reach that conclusion above 0.005 per cent |
Two ranges appear in that table and they are two thousand-fold apart. The efficacy and penetration studies used 10 per cent. The trials at a clinical endpoint used 0.005 to 0.05 per cent, and the industry panel's 2025 conclusion is bounded at 0.005 per cent.
This site does not convert those into a comparison, and the reason is specific. Whether a percentage refers to the peptide itself or to a supplied solution that is already dilute changes the arithmetic entirely, and that question was not resolved from the sources read for this page. A multiplier stated without resolving it would be a number invented on the page.
What can be said without resolving it is that the concentration a study used is a property of that study. A figure from the founding paper is not a figure for a finished product, and a figure from a trial in blepharospasm is not a figure for anything sold for wrinkles.
Nothing here is a use instruction. Talk to a licensed clinician about anything concerning your health.
Main routes people compare, and what each source class actually reported, are set out on the documented protocols page.
Reported effects and what has been measured
What the industry safety panel concluded
The Expert Panel for Cosmetic Ingredient Safety published its assessment of this ingredient in 2025. Its conclusion has two halves and both belong on this page: a conclusion of safety in cosmetics in the present practices of use, bounded at concentrations up to 0.005 per cent, and a statement that the available data are insufficient to reach that conclusion at concentrations greater than 0.005 per cent.
The second half is a statement about what has been submitted, not a finding that anything is harmful. A reader who takes it as a warning has read it wrong, and a page that omits it has left out the operative limit.
This site does not describe any compound as safe. The sentence above is a named panel's dated conclusion, reported as that. [In-vitro] [7]
What was observed in the trials
The published blepharospasm trial reports no significant adverse events across 24 participants.
The second trial posted six event terms across arms of 3, 2 and 3, and the safety record for this ingredient reproduces them with their counts. Two are serious: an automobile accident in the 0.05 per cent arm and a case of blepharitis in the placebo arm, 1 of 3 each. Four are not: puffiness of the lower eyelid and high blood pressure due to not taking blood pressure medication in the 0.05 per cent arm, and tingling in both eyelids after cream application and weakness following botulinum toxin injection in the placebo arm, 1 of 3 each. One participant of three in the 0.05 per cent arm withdrew for an adverse event.
Against the accident the registry records that the subject was the driver, that the subject was on study medication, and that the subject reported that worsening of blepharospasm may have contributed to it. That is the registry's own wording, and this block adds no judgment of relatedness to it in either direction. [Human RCT] [5] [18]
The independent cell work
One laboratory measured the ingredient's effect on the proliferation of three cell types and reported a dose-dependent anti-proliferative effect, appearing at concentrations 18 to 10,000 times higher than the reference compound required depending on the cell line.
The authors' stated reason for running the study is worth repeating: the toxicity data available to them came from the manufacturer. That is a comment on the state of the published record rather than on the ingredient. [In-vitro] [13]
Injection, which is not a labelled route
A published case report describes a woman who received injections of this ingredient into the forehead and temples and developed nodules and abscesses at the sites within a week, culture-positive for Mycobacterium abscessus, resolving over five months of antibiotics.
The ingredient is formulated to be applied to the surface of skin. This report is about a procedure rather than about the molecule, and it is here because a reader searching the ingredient will otherwise not meet it. [Anecdote] [14]
What has been measured about Acetyl hexapeptide-8, and what has never been studied
Talk to a licensed clinician about anything concerning your health.
Sourcing and quality
What a credible product should show
This ingredient has an INCI name, which is a real advantage over almost everything else on this site: the label of a finished cosmetic sold in the United States has to declare it, and the declaration is a legal statement rather than a marketing one.
Under the subchapter added by the Modernization of Cosmetics Regulation Act of 2022, a responsible person must register the facility, list the product, hold records substantiating safety, and report serious adverse events. None of that is a review of whether an ingredient does anything, and no pre-market approval exists.
A published analytical study developed a method for detecting this peptide and its oxidised form in finished creams and serums by liquid chromatography and tandem mass spectrometry, and found both forms present in several products. The oxidation point is the methionine in the sequence, which is a property of the molecule rather than of any product.
Red flags
The comparison with an injected muscle relaxant offered as an equivalence rather than as a mechanism analogy. The founding paper itself records much lower efficacy, and the trip from a cream to a neuromuscular junction has been measured.
The 48.9 per cent figure presented without its design. It comes from subjective global assessment in a four week trial with roughly 15 people on placebo.
A paper count for this ingredient's efficacy record. One 60-subject trial and one mouse experiment appear across three 2013 papers.
The two blepharospasm trials left out of an evidence summary. They are the only tests of the marketed mechanism at a clinical endpoint and both have posted results.
Microneedle patch results cited as evidence for a cream. The patch punctures the barrier the whole question is about.
Any claim that the ingredient relaxes a muscle, blocks a nerve signal, or changes anything about the structure of the body. That is a drug claim about a product sold as a cosmetic, and it is the line described in the regulatory section below.
Will it show on a drug test?
This site has not established a position for this ingredient on any anti-doping prohibited list and does not state one. It is a cosmetic applied to the surface of the skin, and the question does not arise in the way it does for the injectables covered elsewhere here.
An athlete with a question about any product should take it to the relevant anti-doping authority rather than to a page.
Storage
No storage guidance is given here. A finished cosmetic carries its own, and the analytical work above found the peptide's oxidised form present in products alongside the intact molecule, which is a formulation-stability question a product's manufacturer answers rather than this page.
Regulatory status, as of 23 August 2026
| Body | Position | Date | Document |
|---|---|---|---|
| FDA | A listed cosmetic ingredient. No pre-market approval of a cosmetic ingredient exists and none is required | Checked 23 August 2026 | 21 USC 321 and subchapter VI of the Federal Food, Drug, and Cosmetic Act |
| US Congress | The Modernization of Cosmetics Regulation Act of 2022 added facility registration, product listing, safety substantiation records and serious adverse event reporting. It added no efficacy requirement | Enacted 29 December 2022 | Public Law 117-328, division FF, title III, subtitle E |
| FDA | Cosmetic labelling requirements, including the declaration of ingredients | Checked 23 August 2026 | 21 CFR part 701 |
| Expert Panel for Cosmetic Ingredient Safety | Safe in cosmetics in the present practices of use at concentrations up to 0.005 per cent. Available data insufficient to make that determination above 0.005 per cent | Published 2025 | Int J Toxicol, PMID 40673537 |
| ClinicalTrials.gov | Six registered records, four testing the ingredient on its own, two with posted results | Swept 23 August 2026 | ClinicalTrials.gov v2 API |
The line that matters for this ingredient is not approval, because it does not need one. It is the line between a cosmetic claim and a drug claim, and this ingredient sits closer to it than almost anything else lawfully sold.
A cosmetic is a product intended to affect appearance. A product intended to affect the structure or a function of the body is a drug, and a drug needs an approval this ingredient does not have. A claim that a cream makes lines look softer is a cosmetic claim. A claim that it stops a nerve ending signalling a muscle describes a function of the body.
That gap is where the whole marketing vocabulary of this category lives. The mechanism is what makes the ingredient interesting and the mechanism is the part that cannot lawfully be claimed on a cosmetic label, so it migrates into the advertising around the product instead. Reading a page about this ingredient with that division in mind explains most of what is on it.
This section is dated and re-checked on review. It records documents and their dates, not evidence about an effect, and carries no evidence tier for that reason.
Acetyl hexapeptide-8 compared with other cosmetic peptides
| Compound | Evidence grade | What the human record covers | Read more |
|---|---|---|---|
| Acetyl octapeptide-3 | Graded on its own page | The eight amino acid extension of this sequence, sold as the stronger version. No registered trial and no study testing it on its own | /peptides/snap-8/ |
| Palmitoyl pentapeptide-4 | Graded on the cosmetic group page | A different mechanism entirely: a collagen fragment sold as a signal rather than as a blocker. Its evidence rests on one manufacturer-authored trial | /peptides/groups/cosmetic/#matrixyl |
| GHK-Cu, topical | Graded on the cosmetic group page | The lawful topical form of a molecule sold elsewhere as an injectable, and the one place on this site where the same compound appears in both categories | /peptides/groups/cosmetic/#ghk-cu-topical |
| An injected botulinum toxin | Not covered as a compound on this site | An approved medicine that acts on the same protein complex by cutting one of its proteins, delivered into the muscle rather than onto the skin above it | Described in the mechanism section above |
The comparison readers actually search is with the eight amino acid version, and it has its own page because the naming alone traps people.
The comparison worth understanding is with the injected medicine, and the useful part of it is not potency. It is delivery. One is placed into the muscle. The other has to cross a barrier built to stop water-soluble molecules, and how far it gets has been measured.
What Acetyl hexapeptide-8 typically costs
Frequently asked questions
Is acetyl hexapeptide-8 the same as Argireline?
Yes. Argireline is a trade name for the ingredient, and acetyl hexapeptide-8 is the INCI name that appears on a label. It was listed as acetyl hexapeptide-3 under the older nomenclature and both names remain in circulation for the same molecule.
Has it been tested in humans?
Yes, six times on the registry. Four records test the ingredient on its own and two carry it inside a multi-ingredient product. Two of the four have posted results, and two completed and posted nothing.
Does it work like an injected muscle relaxant?
It is designed to act on the same protein complex, by competing with part of it rather than by cutting it. The founding paper describes much lower efficacy than the toxin, and the mechanism requires the peptide to reach a nerve ending below the dermis.
How far into skin does it actually get?
An FDA laboratory applied it at 10 per cent to human cadaver skin for 24 hours and measured every layer. It found 0.22 per cent of the applied dose in the outer layer, 0.01 per cent in the epidermis, and none in the dermis or the fluid beneath the skin.
What did the blepharospasm trials find?
The first randomised 24 patients and posted a primary result of 3.71 months against 3.03 months, which its own published abstract calls a trend. The second raised the concentration ten-fold, enrolled eight participants across three arms, posted results where placebo scored best at every timepoint, and is recorded as terminated.
Why was the second trial stopped?
The registry's field for that reason is empty and nothing else on the record states one. This site does not infer it.
What is the 48.9 per cent figure?
The total anti-wrinkle response reported by subjective global assessment in a randomised placebo-controlled trial of 60 Chinese subjects over four weeks, allocated three to one, which puts roughly 15 people on placebo. The same figure appears in two journals in the same year.
Is acetyl hexapeptide-8 safe?
This site takes no position on that for any compound. What is on the record is a dated conclusion from the Expert Panel for Cosmetic Ingredient Safety, published in 2025: a conclusion of safety in cosmetics bounded at concentrations up to 0.005 per cent, and a statement that available data are insufficient to reach that conclusion at higher concentrations.
Is it legal to sell in the United States?
Yes. It is a listed cosmetic ingredient, and a product containing it may be sold provided the responsible person registers the facility, lists the product, holds safety substantiation records and reports serious adverse events. Nothing in that requires evidence of effect.
How does it compare with the eight amino acid version?
No published study ranks them, in any design. Every comparative potency statement in circulation traces to unpublished supplier material, and the extension has no registered trial and no study testing it on its own.
Why does this page cite trials in an eye condition?
Because they are the only place the marketed mechanism was tested against a number rather than an appearance, on the thinnest skin on the body, by a national institute, with both sets of results posted. An evidence summary that leaves them out is citing half the record.
References
- Blanes-Mira C, Clemente J, Jodas G, Gil A, Fernández-Ballester G, Ponsati B, Gutierrez L, Pérez-Payá E, Ferrer-Montiel A. A synthetic hexapeptide (Argireline) with antiwrinkle activity. Int J Cosmet Sci. 2002. PMID 18498523 DOI 10.1046/j.1467-2494.2002.00153.x
- Wang Y, Wang M, Xiao S, Pan P, Li P, Huo J. The anti-wrinkle efficacy of argireline, a synthetic hexapeptide, in Chinese subjects: a randomized, placebo-controlled study. Am J Clin Dermatol. 2013. PMID 23417317 DOI 10.1007/s40257-013-0009-9
- Wang Y, Wang M, Xiao XS, Pan P, Li P, Huo J. The anti wrinkle efficacy of synthetic hexapeptide (Argireline) in Chinese Subjects. J Cosmet Laser Ther. 2013. PMID 23607739 DOI 10.3109/14764172.2012.759234
- Wang Y, Wang M, Xiao XS, Huo J, Zhang WD. The anti-wrinkle efficacy of Argireline. J Cosmet Laser Ther. 2013. PMID 23464592 DOI 10.3109/14764172.2013.769273
- Lungu C, Considine E, Zahir S, Ponsati B, Arrastia S, Hallett M. Pilot study of topical acetyl hexapeptide-8 in the treatment for blepharospasm in patients receiving botulinum toxin therapy. Eur J Neurol. 2013. PMID 23146065 DOI 10.1111/ene.12009
- Kraeling ME, Zhou W, Wang P, Ogunsola OA. In vitro skin penetration of acetyl hexapeptide-8 from a cosmetic formulation. Cutan Ocul Toxicol. 2015. PMID 24754410 DOI 10.3109/15569527.2014.894521
- Johnson W Jr, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD, Liebler DC, Marks JG Jr, Peterson LA, Shank RC, Slaga TJ, Snyder PW, Fiume M, Heldreth B. Safety Assessment of Acetyl Hexapeptide-8 Amide as Used in Cosmetics. Int J Toxicol. 2025. PMID 40673537 DOI 10.1177/10915818251340391
- Zdrada-Nowak J, Surgiel-Gemza A, Szatkowska M. Acetyl Hexapeptide-8 in Cosmeceuticals-A Review of Skin Permeability and Efficacy. Int J Mol Sci. 2025. PMID 40565185 DOI 10.3390/ijms26125722
- An JH, Lee HJ, Yoon MS, Kim DH. Anti-Wrinkle Efficacy of Cross-Linked Hyaluronic Acid-Based Microneedle Patch with Acetyl Hexapeptide-8 and Epidermal Growth Factor on Korean Skin. Ann Dermatol. 2019. PMID 33911590 DOI 10.5021/ad.2019.31.3.263
- Hoppel M, Reznicek G, Kählig H, Kotisch H, Resch GP, Valenta C. Topical delivery of acetyl hexapeptide-8 from different emulsions: influence of emulsion composition and internal structure. Eur J Pharm Sci. 2015. PMID 25497319 DOI 10.1016/j.ejps.2014.12.006
- Lim SH, Sun Y, Thiruvallur Madanagopal T, Rosa V, Kang L. Enhanced Skin Permeation of Anti-wrinkle Peptides via Molecular Modification. Sci Rep. 2018. PMID 29371611 DOI 10.1038/s41598-017-18454-z
- Mortazavi SM, Moghimi HR. Skin permeability, a dismissed necessity for anti-wrinkle peptide performance. Int J Cosmet Sci. 2022. PMID 35302659 DOI 10.1111/ics.12770
- Grosicki M, Latacz G, Szopa A, Cukier A, Kieć-Kononowicz K. The study of cellular cytotoxicity of argireline - an anti-aging peptide. Acta Biochim Pol. 2014. PMID 24644551
- Chen CF, Liu J, Wang SS, Yao YF, Yu B, Hu XP. Mycobacterium abscessus infection after facial injection of argireline: A case report. World J Clin Cases. 2021. PMID 33748252 DOI 10.12998/wjcc.v9.i8.1996
- Kluczyk A, Ludwiczak J, Modzel M, Kuczer M, Cebrat M, Biernat M, Bąchor R. Argireline: Needle-Free Botox as Analytical Challenge. Chem Biodivers. 2021. PMID 33482052 DOI 10.1002/cbdv.202000992
- Lum K, M Hirpara M, Pham C, Nguyen M, Mesinkovska N. Acetyl Hexapeptide-8 as a Topical Alternative to Botulinum Toxin: A Review of the Literature. J Drugs Dermatol. 2025. PMID 40196949
- ClinicalTrials.gov. NCT00942851, a randomized triple-masked placebo-controlled trial of topical acetyl hexapeptide-8 at 0.005 per cent in 24 patients with blepharospasm, sponsored by the National Institute of Neurological Disorders and Stroke with BCN Peptides as collaborator. Completed October 2010. Results posted: primary outcome 3.71 months active against 3.03 months placebo; disability scale change at three months 30.89 per cent active against 32.32 per cent placebo. No statistical analysis is posted for any outcome. Read through the v2 API on 23 August 2026. ClinicalTrials.gov. 2026. NCT00942851
- ClinicalTrials.gov. NCT01750346, a randomized double-masked trial of topical acetyl hexapeptide-8 at 0.05 and 0.025 per cent against placebo in blepharospasm, sponsored by the National Institute of Neurological Disorders and Stroke, enrolling 8 participants across three arms. Recorded as TERMINATED with the reason field empty. Results posted: Jankovic scale at two months, where a higher score is worse, 6 and 7 in the active arms against 4.33 on placebo; one withdrawal for an adverse event in the highest-concentration arm. The registry's own background text states the trial was run because the concentration used in the earlier study was not very effective. Read through the v2 API on 23 August 2026. ClinicalTrials.gov. 2026. NCT01750346
- ClinicalTrials.gov. NCT01381484, a randomized triple-masked Phase 3 trial of a 10 per cent Argireline gel in 70 participants with periorbital wrinkles, sponsored by Mahidol University with Pacific Health Foundation as collaborator, completed September 2009. No results are posted and no publication was located. Read through the v2 API on 23 August 2026. ClinicalTrials.gov. 2026. NCT01381484
- ClinicalTrials.gov. NCT02597777, a randomized quadruple-masked pilot trial of topical acetyl hexapeptide-8 at 10 per cent in a lotion base against the same base, in 14 participants, primary outcome physician-graded shine at four weeks, sponsored by the University of California, Davis, completed February 2016. No results are posted and no publication was located. Read through the v2 API on 23 August 2026. ClinicalTrials.gov. 2026. NCT02597777
- ClinicalTrials.gov. Registry sweep for argireline, acetyl hexapeptide-8, acetyl hexapeptide-3, acetyl octapeptide-3, acetyl octapeptide-8 and SNAP-8 peptide, run through the v2 API on 23 August 2026. Six records returned for the hexapeptide, of which four name it as the isolated intervention and two carry it inside a multi-ingredient product (NCT03878381, a compounded cream listing twelve actives in 10 participants; NCT06143033, a single-arm eye serum with twenty-four declared ingredients in 35 participants). The three octapeptide queries each returned no record. ClinicalTrials.gov. 2026. ClinicalTrials.gov
- United States Congress. Consolidated Appropriations Act, 2023, Public Law 117-328, enacted 29 December 2022. Division FF, title III, subtitle E is the Modernization of Cosmetics Regulation Act of 2022, which adds subchapter VI of the Federal Food, Drug, and Cosmetic Act. govinfo. 2022. Source document
- Office of the Law Revision Counsel, United States House of Representatives. Federal Food, Drug, and Cosmetic Act, title 21 of the United States Code: section 321 for the definitions of drug and cosmetic, and subchapter VI sections 364 to 364d for cosmetic definitions, adverse events, registration and product listing, and safety substantiation. Checked 23 August 2026. United States Code. 2026. Source document
- Office of the Federal Register and Government Publishing Office. Cosmetic labeling, title 21 of the Code of Federal Regulations, part 701. Checked 23 August 2026. Electronic Code of Federal Regulations. 2026. Source document