Argireline (acetyl hexapeptide-8)

Origin and structure

Argireline is the trade name of acetyl hexapeptide-8, a chain of six amino acids (glutamic acid, glutamic acid, methionine, glutamine, arginine, arginine) with an acetyl group capping the start and an amide group the end: Ac-Glu-Glu-Met-Gln-Arg-Arg-NH2, or Ac-EEMQRR-NH2 in one-letter code. The sequence is copied from the start (the N-terminal end) of SNAP-25, a protein that nerve endings need to release their signal.

It came out of a deliberate search for a molecule that would copy the wrinkle-smoothing effect of botulinum toxin without its toxicity. The Spanish company Lipotec patented it (WO 00/64932), and researchers at the Miguel Hernández University in Alicante, Spain, described it in 2002 (Blanes-Mira et al.). For the first medical trial, at the US National Institutes of Health in 2009 and 2010, the creams were made by BCN Peptides, a company of the same Lipotec group.

On ingredient lists it appears as acetyl hexapeptide-8, the name used in CosIng, the European Commission's database of cosmetic ingredients, where its CAS number is 616204-22-9. Acetyl hexapeptide-3 is another name for the same peptide that still turns up in research papers, and the US Cosmetic Ingredient Review assessed it under the synonym acetyl hexapeptide-8 amide. SNAP-8, or acetyl octapeptide-3, is the same chain with two extra amino acids at the end.

How it is thought to work

To make a muscle contract, a nerve ending releases acetylcholine from small vesicles. These can only fuse with the cell membrane once the SNARE complex has formed, a bundle of proteins that includes SNAP-25. Botulinum toxin type A cuts SNAP-25 and so blocks the signal. Argireline copies a piece of SNAP-25 and is meant to compete with the real protein while the complex assembles, damping the release rather than blocking it; it cuts nothing.

The laboratory evidence for this comes mainly from the 2002 paper. There, Argireline interfered with the formation or stability of the SNARE complex and inhibited neurotransmitter release with a potency similar to that of botulinum toxin A, but with a much smaller maximum effect. These were laboratory experiments, not measurements in facial muscle.

The bigger doubt is whether it gets there. The nerve endings that move the facial muscles lie beneath the epidermis and the dermis. When FDA scientists left an emulsion containing 10% acetyl hexapeptide-8 on human donor skin for 24 hours, most of it washed off: 0.22% of the applied amount stayed in the outer horny layer, 0.01% reached the living epidermis, and none was found in the dermis or in the fluid beneath the skin (Kraeling et al., 2015). Researchers have since tried other emulsions, microneedle patches and chemically modified versions to get more of it into the skin, mostly in laboratory tests.

Is Argireline approved?

Not as a medicine. We found no authorised medicine containing acetyl hexapeptide-8 in the EU, the Netherlands or the United States. Its legal home is cosmetics.

In the EU, acetyl hexapeptide-8 is listed in CosIng with the functions humectant and skin conditioning, and it appears on none of the Cosmetics Regulation's annexes of banned or restricted substances, so no specific limit applies. Ingredients like this need no approval in advance, but every finished cosmetic must have a safety assessment and be notified in the EU's CPNP portal before it goes on sale; in the Netherlands the NVWA supervises this. The regulation also states that a product intended to be injected is not a cosmetic.

In the United States Argireline is a cosmetic ingredient, not an approved drug. Cosmetics and their ingredients, apart from colour additives, need no FDA approval before they go on sale, but a product intended to affect the structure or a function of the body is a drug in law, whatever it is called. A cream that claims to relax the facial muscles would therefore be a drug in law, which is why cosmetic claims stop at how lines look. The Cosmetic Ingredient Review (CIR), the US expert panel that assesses cosmetic ingredients, concluded in 2025 that acetyl hexapeptide-8 is safe in cosmetics at concentrations up to 0.005%, and that the data are insufficient to call it safe at higher concentrations.

In sport Argireline is not named on the WADA Prohibited List. Class S0 prohibits at all times any pharmacological substance that no health authority has approved for human therapeutic use, and the 2027 list, in force from 1 January 2027, names peptides among its examples. The list does not deal with cosmetics that contain such ingredients. The Dopingautoriteit applies the same list in the Netherlands.

What the research shows

Beyond the laboratory work there is a handful of human studies. They are small, most lasted four to eight weeks, and they disagree:

• Blanes-Mira et al., 2002 (the team that designed the peptide): besides the laboratory work, 10 healthy women applied an oil-in-water emulsion described as containing 10% of the peptide for 30 days. Wrinkle depth fell by up to 30%, against up to 10% with the emulsion alone, according to a later summary of the paper. The authors also reported no toxicity by mouth and no primary skin irritation at high doses.
• Wang et al., 2013 (a hospital team in Xi'an, China): 60 adults were randomised 3:1 to Argireline or placebo, applied to the skin around the eyes twice a day for four weeks. Investigators rated 48.9% of the Argireline group as improved against none on placebo, and on silicone skin replicas roughness fell with Argireline (p < 0.01) but not with placebo. The objective measurement covered skin roughness, not wrinkle depth, and the abstract names no concentration or sponsor.
• Henseler, 2023 (no competing interests declared): 19 women used a hyaluronic-acid serum twice a day for four weeks, with Argireline in the serum for one half of the face only; neither they nor the researchers knew which side. Wrinkle scores from a Visia camera fell slightly on both sides, with no significant difference between them (p = 0.829), and the author concluded that Argireline is not an alternative to botulinum toxin.
• Raikou et al., 2017 (Technological Educational Institute of Athens): 24 healthy volunteers were randomised to one of four creams for 60 days: with acetyl hexapeptide-3 (Argireline), with tripeptide-10 citrulline, with both, or with neither. Against the cream without peptide, the Argireline group differed significantly on one of the two skin-roughness measures at day 20 but not at day 60, and lost less water through the skin at days 20 and 40. The authors conclude that this confirms its anti-wrinkle activity; with 24 people spread over four groups, the evidence is thin.
• Aruan et al., 2023 (Jakarta, Indonesia, funded by a cosmetics company): in a double-blind trial, 21 women aged 26 to 55, 7 per group, applied a cream with acetyl hexapeptide-3 (Argireline), one with palmitoyl pentapeptide-4 (Matrixyl) or a placebo cream around the eyes twice a day for eight weeks. None of the skin measurements showed a significant difference, on the crow's-feet grading scale the placebo group improved at least as much as the Argireline group, and the authors judged the palmitoyl pentapeptide-4 cream the better of the two peptides. The concentrations were not reported.
• Lungu et al., 2013 (US National Institutes of Health): the first medical trial, in 24 people with blepharospasm, a spasm of the eyelid-closing muscle treated with botulinum toxin injections. After their usual injection they applied a 0.005% cream or an identical placebo cream to the eyelids twice a day. Symptoms returned after 3.7 months on average with the peptide against 3.0 months on placebo, a difference that was not statistically significant, although 4 of the 12 on the peptide stayed in control clearly longer (3.3 to 7.1 months). A follow-up trial of 0.025% and 0.05% creams enrolled 8 patients and was terminated in 2015 (NCT01750346).
• Oily skin (University of California, Davis, NCT02597777, 14 participants enrolled; published as Shi et al., 2022): one half of the face received a lotion with acetyl hexapeptide-8 and the other a placebo lotion for four weeks. Sebum production fell by about 10% more on the peptide side, a trend that was not significant (p = 0.16).
• Unpublished and not studied: a placebo-controlled trial of a 10% Argireline gel in 70 people at Mahidol University in Thailand (NCT01381484) was completed in 2009, but we found no published results. No trial has tested injection, and we found no trial that compared Argireline with botulinum toxin injections.

Argireline versus Botox, SNAP-8 and Matrixyl

The comparison with Botox holds for the target, not for the effect. Botulinum toxin type A is injected into the muscle and cuts SNAP-25, so the signal stays blocked until the nerve endings recover; in blepharospasm the injections are usually repeated about every three months. Argireline is spread on the skin, cuts nothing, and in the laboratory reached a much smaller maximum effect than the toxin. We found no trial comparing Argireline cream with botulinum toxin injections, and in the one trial that added it to the injections it did not significantly prolong their effect.

SNAP-8 (acetyl octapeptide-3) takes the same six amino acids and adds alanine and aspartic acid at the end. It has no published study of its own, and no study has compared the two, so whether the longer chain does anything more in people is unknown. Matrixyl (palmitoyl pentapeptide-4) rests on a different idea altogether: a procollagen fragment meant to signal the collagen-making cells of the dermis, not to damp nerve signals. The one trial that compared the two, in 21 Indonesian women (Aruan et al., 2023), found no significant difference on its skin measurements; the authors favoured the palmitoyl pentapeptide-4 cream, but the study was too small to settle the question.

Side effects and safety

On the skin, Argireline has caused few problems in studies. The 2002 paper reported no toxicity by mouth and no primary skin irritation at high doses, and the 19-woman split-face study saw no significant adverse events, allergic reactions or skin irritation. In the 21-woman Indonesian trial, one of the seven women on the Argireline cream reported itching, two stinging and one burning, against itching in two and burning in two of the seven on placebo; there were no serious adverse events. In the NIH eyelid trial, 4 of the 24 patients, two on the peptide and two on placebo, had mild eyelid irritation that cleared by itself; the doctors put it down to the thick cream rather than the peptide. The NIH researchers also cite the maker's toxicology report, which found no toxicity at 0.05% and above, but that report has not been published.

The safety verdict has limits. The CIR panel found acetyl hexapeptide-8 safe in cosmetics up to 0.005%, the concentration used in the NIH trial, and found the data insufficient to judge higher concentrations. No trial has tested injection. One case report from China describes a 45-year-old woman who developed redness, nodules and abscesses a week after Argireline was injected into her forehead and temples; cultures grew the bacterium Mycobacterium abscessus, and she needed five months of antibiotics. The authors link the infection to the cosmetic procedure and call for standardised procedures; no study has examined what injected acetyl hexapeptide-8 does in people.

Frequently asked questions

Does Argireline work like Botox?

Only on paper, and far more weakly. Botulinum toxin is injected into the muscle and cuts the nerve protein SNAP-25, which blocks the signal for months. Argireline goes on the skin and copies a piece of SNAP-25 to compete with it, without cutting anything; in the laboratory its maximum effect was much smaller than the toxin's, and on human donor skin almost none of it got past the outer layer. In the only trial that added it to Botox injections, for the eyelid spasm blepharospasm, it did not significantly prolong their effect, and we found no trial comparing the two directly.

Does Argireline really work against wrinkles?

The evidence is thin and mixed. In a placebo-controlled trial in 60 Chinese adults, investigators rated 48.9% of the Argireline group as improved after four weeks, against none on placebo. The developers' first study, in 10 women, reported wrinkles up to 30% shallower after 30 days. But an independent double-blind split-face study in 19 women found no difference after four weeks between the sides with and without Argireline, and in a double-blind trial in 21 Indonesian women none of the skin measurements differed significantly after eight weeks. All of these studies were small and short.

What is the difference between Argireline and SNAP-8?

SNAP-8 (acetyl octapeptide-3) is Argireline (acetyl hexapeptide-8) with two more amino acids, alanine and aspartic acid, at the end; both copy the same stretch of the nerve protein SNAP-25. Argireline has the larger research record, a handful of small trials with mixed results. SNAP-8 has no published study of its own, and no study has compared the two directly, so there is no evidence that the longer peptide works better.

Is acetyl hexapeptide-3 the same as acetyl hexapeptide-8?

Yes. Both names refer to the same peptide, Ac-Glu-Glu-Met-Gln-Arg-Arg-NH2, sold as Argireline. Acetyl hexapeptide-8 is the ingredient name in the EU database CosIng, which does not list acetyl hexapeptide-3, but research papers still use both. The US Cosmetic Ingredient Review assessed it as acetyl hexapeptide-8 amide and treats that as a synonym.

Is Argireline legal in the Netherlands?

As a cosmetic ingredient, yes: acetyl hexapeptide-8 is listed in the EU ingredient database CosIng and is not banned or restricted, and a cream or serum containing it is legal if the finished product meets the Cosmetics Regulation, which the NVWA enforces in the Netherlands. It is not a medicine, so it may not be sold or advertised as a treatment. Pure peptide sold as research material has not been through the safety assessment a finished cosmetic needs, and a product meant for injection is never a cosmetic.

Can Argireline be injected?

No trial has tested it by injection, so there are no human data on its effect or safety by that route. One case report from China describes a 45-year-old woman who developed nodules and abscesses a week after Argireline was injected into her forehead and temples; the cause was the bacterium Mycobacterium abscessus, and she needed five months of antibiotics. Under EU law a product intended for injection is not a cosmetic, and no medicine containing acetyl hexapeptide-8 has been authorised.

Storage and handling

Store according to product-label instructions and batch handling notes. Lyophilized research peptides are commonly kept dry, protected from light, and handled with clean laboratory technique.

References

Checked against these sources on 28 October 2026.

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