Acetyl Tetrapeptide-40 (Telangyn)_Dosage, benefits & legal status
Also known as Telangyn, Acetyl Tetrapeptide 40, Ac-Ala-Thr-Asn-Thr, acetyl-ATNT
Tested in the lab at a thousand times the strength it reaches your face.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Acetyl Tetrapeptide-40 (Telangyn)?
Plain language first. The technical label stays, but it never stands alone.Overview
This is a skincare ingredient aimed at facial redness, the kind people associate with rosacea. The idea behind it is reasonable: in rosacea, a natural antimicrobial molecule called LL-37 builds up in the skin and drives inflammation, and this peptide is meant to blunt that response. There are two things worth knowing before trusting it. The first is a concentration problem. Every laboratory result behind this ingredient was produced at between 0.25 and 10 milligrams per milliliter. Used as the supplier recommends, the peptide reaches skin at roughly 0.01 milligrams per milliliter, so the enzyme experiments ran at hundreds to a thousand times the strength anyone actually applies. The second is that the only human test was 20 people with mild rosacea using the cream for four weeks, with no placebo group to compare against. That does not make the ingredient useless. It does mean the evidence is a patent, not a literature.
Acetyl Tetrapeptide-40 is a four-residue cosmetic peptide, acetyl-Ala-Thr-Asn-Thr, sold by Lubrizol under the trade name Telangyn for facial redness. The ingredient the formulator buys is a dilute aqueous solution: Lubrizol's declared composition is water, the peptide, and caprylyl glycol, recommended at 2% in a finished product. The mechanism claim concerns LL-37, the antimicrobial peptide implicated in rosacea, and the only data of any kind sits in a Lipotec patent rather than in the literature. No peer-reviewed study of this peptide exists, and FDA's substance registry holds no record of it.
What it's used for
Sold as a cosmetic ingredient for facial redness and the look of dilated vessels, in leave-on creams and serums. Present in finished products on sale now, including Circadia's Chrono-Calm Serum and AE.R Skinlab's RE:GEN Serum.
How does Acetyl Tetrapeptide-40 (Telangyn) work?
What it does in the body, and where.The target here is a molecule this site already covers, and the story is unusually clean in theory and unusually thin in evidence.
- 01LL-37 is the villain of the story, and it is on this site alreadyLL-37 is a natural antimicrobial peptide. In rosacea it accumulates in the skin in an altered form and drives inflammatory signaling, so it is one of the better-supported mechanistic accounts of why rosacea skin behaves as it does. This peptide is positioned against that process. Anyone arriving from the LL-37 page should note the relationship is opposition rather than kinship: the two are not structurally related and this one is four residues long.
- 02What the cell experiments actually showedIn the patent, skin cells were provoked with LL-37 at 50 micrograms per mL and the peptide was added at 0.1 and 0.5 mg per mL. Interleukin-6 came down to about 93 to 95% of untreated baseline, against 122% for cells given LL-37 alone. Interleukin-8 came down to 109% against 143% for LL-37 alone. Read the second one carefully: IL-8 stayed above baseline, so the effect is a partial brake on the inflammatory rise rather than a return to normal.
- 03The concentration problem, stated plainlyThe same patent reports complete collagenase inhibition at 10 mg per mL and 29% at 2 mg per mL, tyrosinase inhibition of 86% at 4 mg per mL, and improved fibroblast survival after simulated sunlight at 1 and 10 mg per mL. Used as directed, the peptide arrives at about 0.01 mg per mL. None of those experiments was run anywhere near a concentration skin will see, and the supplier does not address the gap.
- 04One result points the wrong wayThe melanocyte experiment gave melanin content at 45.7% of control at 0.25 mg per mL and 55.8% at 0.625 mg per mL. More peptide did less. A dose-response that reverses is a reason to hold a finding loosely, and it is the kind of detail that does not survive the trip into marketing copy.
What else is it used for?
Each group carries its own evidence level.Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
The only human test
Early research- human-early20 volunteers with slight rosacea applied a cream containing the peptide twice daily for four weeks. Erythema fell about 9.0% at one week and 19.2% at four weeks.
- No dataNo control or vehicle arm is described. In a four-week redness study without a placebo, moisturizing alone can produce movement of this size, so the figure cannot be attributed to the peptide.
- No dataThe study lives in the patent, not in a journal. Sourcing tier: read in the patent text; the results table rendered garbled, so only the erythema column is reported here.
Laboratory work, and the concentrations it used
Early research- Lab studyInterleukin-6 at 94.65% and 92.90% of baseline with peptide at 0.1 and 0.5 mg per mL, against 122.28% for cells given LL-37 alone. Quadruplicate wells.
- Lab studyInterleukin-8 at 109.39% with peptide at 0.5 mg per mL against 142.65% for LL-37 alone, so it remained above untreated baseline.
- Lab studyCollagenase inhibition 100% at 10 mg per mL and 29.21% at 2 mg per mL, against 95.19% for the positive control. Tyrosinase inhibition 86.45% at 4 mg per mL against 85.79% for kojic acid. Fibroblast survival after simulated sunlight 20.03% untreated, 52.37% at 1 mg per mL, 63.25% at 10 mg per mL.
- No dataMelanin content 45.7% of control at 0.25 mg per mL but 55.8% at 0.625 mg per mL, so the higher dose did less. A reversed dose-response.
- No dataEvery figure above comes from concentrations of 0.25 to 10 mg per mL against an in-use level of roughly 0.01 mg per mL. This is the single most important thing on the page.
Identity, and what the registries do not have
none- lab-analysisThe INCI name is confirmed in the European cosmetic ingredient registry, with declared function skin conditioning and synthetic origin. That entry carries no CAS number.
- No dataTwo CAS numbers circulate and they disagree: 1472633-28-5, with formula C17H29N5O9 and molecular weight 447.44 on two commercial chemical directories, and 928006-89-7 on a single source whose own page contradicts itself on other figures. The first is the stronger of the two, because that formula is what acetyl-Ala-Thr-Asn-Thr computes to, but no registry confirms either and neither is stated here as settled.
- lab-analysisFDA's substance registry returns no record for this name. Positive control run the same day: the same query shape returns one record for ACETYL TETRAPEPTIDE-15, so the empty result reflects the registry rather than a broken query.
- lab-analysisNo peer-reviewed study of this peptide exists. PubMed reports the exact phrase absent from its phrase index. Europe PMC returns exactly one paper, and that paper mentions the peptide once, inside a table listing the ingredients of a tested lotion, with no result attributable to it.
Where it is sold, and a date conflict in the trade press
Supplement or cosmetic- lab-analysisCircadia's Chrono-Calm Serum lists Acetyl Tetrapeptide-40 in its ingredient list and separately names Telangyn as the source, with caprylyl glycol also present, consistent with the Lubrizol solution being the input.
- lab-analysisAE.R Skinlab's RE:GEN Serum publishes a 24-ingredient list with Acetyl Tetrapeptide-40 at position 19. The trade name is not mentioned there.
- No dataTwo 2012 trade reports of the same four-week test disagree. One gives erythematic intensity down 19.2%, redness down 17.7%, extent down 17.9% and roughness down 7.5%. The other reports redness down 7.5%. One outlet transposed a value, so the patent is the source used here and neither outlet is relied on.
The first and largest error is treating the laboratory numbers as describing skin. Complete collagenase inhibition sounds decisive until you notice it required 10 mg per mL, about a thousand times what the supplier's own recommended use level delivers. The second is quoting the 19.2% redness reduction without its design: 20 people, four weeks, no control group, published in a patent. The third is saying Telangyn is Acetyl Tetrapeptide-40. Telangyn is a dilute aqueous solution of it, declared as water, the peptide and caprylyl glycol, and intended for use at 2%. The fourth is the sequence's provenance. Acetyl-Ala-Thr-Asn-Thr is correct and it comes from a Lipotec patent, not from Lubrizol's marketing, and Lubrizol's own page does not state a sequence at all. One caveat belongs with that: the patent never uses the words Acetyl Tetrapeptide-40 or Telangyn, so tying the two together is an inference from a matching company, a matching date and a claim-for-claim matching activity profile. The fifth is publishing a CAS number as though one were settled. Two are in circulation and no registry carries either.
The published record
0
Papers about Acetyl Tetrapeptide-40 (Telangyn)
Searched: acetyl tetrapeptide-40, Telangyn, Ac-Ala-Thr-Asn-Thr, acetyl-ATNT.
Left out: LL-37 (THE critical rejection and an unusual one: LL-37 is on this site and is the molecule this peptide is meant to COUNTERACT, not a relative. Every cell experiment behind this ingredient provokes skin cells WITH LL-37 at 50 micrograms/mL and then measures whether the peptide blunts the response. A naive merge would invert the relationship); acetyl tetrapeptide-2 (a DIFFERENT cosmetic tetrapeptide on this site, sequence KDVY, sold as Uplevity, also a Lubrizol material. Same prefix, same length, different sequence and different claim); acetyl tetrapeptide-5 (another on this site, AHSH, for puffiness. The acetyl-tetrapeptide numbering series is the single biggest collision risk for this card); acetyl tetrapeptide-9 (another on this site, QDVH, for firmness via lumican); acetyl tetrapeptide-11 (another on this site, PPYL); acetyl tetrapeptide-15 (another on this site, YPFF, AND the positive control used to prove this compound's GSRS absence is real (it returns UNII 6K389LE0MV where tetrapeptide-40 returns total 0)); acetyl hexapeptide-37 (a different Lubrizol cosmetic peptide on this site that names Circadia and Dermalogica on its own card, so brand-level searches collide); Lipotec (the patent applicant and originator. A company name spanning a large cosmetic peptide portfolio, several items of which are already on this site); rosacea (the target condition, far too broad, and the subject of real pharmaceutical treatments this ingredient is not); palmitoyl tripeptide-38 (unrelated, but it is the peptide in a sibling product of the same supplier line, so supplier-level searches return it).
Europe PMC was searched on November 11, 2026 for these terms and returned nothing.
Counted from Europe PMC indexing, not read by a person.
At a glance
Four things to know about Acetyl Tetrapeptide-40 (Telangyn)
Evidence
Cosmetic
Category
Skin and cosmetic
Common vial
Varies
Half-life
Not applicable to a leave-on topical, and none published
How much, and do you cycle it?
The range, and whether you take breaks.2% of the Telangyn solution in a finished product, so roughly 0.001% peptide, as the product directs. Daily and ongoing, as a leave-on product Community practice
A cosmetic ingredient with no established course. The only human test applied a cream twice daily for four weeks, so nothing longer has been measured.
Not applicable to a leave-on topical, and none publishedNo figure
No pharmacokinetic work of any kind has been published for this peptide. For a four-residue peptide in a leave-on cosmetic the question that matters is whether it crosses the stratum corneum at all, and no penetration study was found either.
You can compare this against the whole library to see where it sits.
What does it cost?
Typical dose and cost, in plain numbers.Acetyl Tetrapeptide-40 (Telangyn) is not injected in the forms covered here
It is taken on the skin (cream or serum). Lubrizol recommends the Telangyn solution at 2% of a finished formula. The peptide content of that solution is the figure that matters and Lubrizol does not publish it. Formulator-facing resellers state 0.05%, so 2% of a 0.05% solution puts roughly 0.001% peptide on skin, about 0.01 mg per mL. Treat that number as reseller-derived rather than manufacturer-confirmed. The comparison worth carrying: the patent's enzyme and cell experiments used 0.25 to 10 mg per mL, between twenty-five and a thousand times higher. There is no injected dose and no oral dose.
How do you store it?
Before mixing, and after.Room temperature, out of light. Cap it tight after each use.
Acetyl Tetrapeptide-40 (Telangyn) ships as a cream, gel, or serum. Keep it at room temperature away from sun and heat unless the label says otherwise. Refrigerating an emulsion can split the texture. Watch for color, smell, or separation changes and stop using it if any appear.
What are the side effects and cautions?
Known cautions and warnings for this compound.Who should avoid it
- Treating the laboratory enzyme figures as describing what happens on skin, since they were produced at hundreds to a thousand times the in-use concentration
- Reading the 19.2% erythema reduction as a controlled result, since the study had no placebo arm and ran in 20 people
- Buying a CAS number for this ingredient as settled, since the two in circulation disagree and no registry confirms either
- Expecting it to work like LL-37 itself, already covered here. LL-37 is the molecule this peptide is meant to counteract, not a relative of it
Stop and get help
- A leave-on cosmetic, so there is no course to stop. Discontinue on irritation as with any topical
- New or worsening facial flushing. That needs a clinician rather than a change of serum, because rosacea has treatments that work and this ingredient is not one of them
Common effects
- None published. The patent's four-week human example reports efficacy scores only, and the supplier's product page lists no tolerability data at all.
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Acetyl Tetrapeptide-40 (Telangyn) approved?
And where the numbers on this page come from.Not as a medicine. Acetyl Tetrapeptide-40 (Telangyn) is sold without a prescription as a cosmetic ingredient, which is a different thing from being approved as a drug.
- Approval statusCosmeticSold without a prescription as an ingredient in cosmetics, such as skincare and hair products. The FDA does not approve cosmetics before they are sold, and being easy to buy says nothing about whether it works.
- RouteOn the skin (cream or serum)
- Checked9 November 2026
- DoseFrom the concentration range manufacturers formulate at. This is a product strength, not a dose set by a regulator or a trial.
- Vial sizeFrom what vendors typically list; not a recommendation.
- SourcesLubrizol, Telangyn peptide solution product pageLipotec patent WO2013156493A1COSMILE Europe ingredient record, Acetyl Tetrapeptide-40FDA Global Substance Registration System search, Acetyl Tetrapeptide-40Circadia, Chrono-Calm Serum product pageAE.R Skinlab, RE:GEN Serum product pagePersonal Care Magazine, caring for sensitive skinPremium Beauty News, Lipotec targets skin inflammation
What has happened recently
A cosmetic ingredient, so there is no approval to report in any jurisdiction. The INCI name is registered and carries a declared function of skin conditioning with synthetic origin. FDA's substance registry has no record under this name, verified against a working positive control. The only substantive data is in Lipotec's patent WO2013156493A1, priority April 16, 2012, now showing as ceased, with family members EP2838547A1 and US20150104485A1 visible in search listings but not opened. Lubrizol markets the material today and the patent is Lipotec's; no document opened here states the relationship between the two companies, so none is asserted. Lubrizol publishes no technical bulletin or data sheet for Telangyn that could be found, and a distributor-hosted technical PDF was blocked by this session's network policy, so it remains unread rather than ruled out.
You can compare this against the whole library, or read how to check a seller.
What else is like Acetyl Tetrapeptide-40 (Telangyn)?
Others in Skin and cosmetic, side by side.If you're weighing Acetyl Tetrapeptide-40 (Telangyn), it's worth reading Acetyl Tetrapeptide-5 (Eyeseryl), Acetyl Tetrapeptide-9, and Decapeptide-52 (OS-01) in the same class.
Tested in the lab at a thousand times the strength it reaches your face.
- Dose
- 2% of the Telangyn solution in a finished product, so roughly 0.001% peptide
- How often
- As the product directs
A topical peptide aimed at under-eye puffiness rather than lines.
- Dose
- Serum, per product
- How often
- Daily
The in-vitro numbers are specific and the human evidence is one uncontrolled study the supplier ran.
- Dose
- Set by the product; the laboratory work used 0.74 to 7.4 micrograms per mL
- How often
- As the product directs
A 2.6-year age reversal, measured in a dish from one donor.
- Dose
- Serum, per product
- How often
- Daily
Guides for this compound
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
- How to Read a Peptide COA
What the purity number does and does not tell you, and how to spot an edited report.
- How to Vet a Peptide Vendor
Independent COAs, HPLC purity, and the red flags that mean walk away.
Sources
- Lubrizol, Telangyn peptide solution product page(2026)The manufacturer's own page. Declares the composition as water, Acetyl Tetrapeptide-40 and caprylyl glycol, with a recommended use level of 2% and 99.49% natural origin content under ISO 16128. Claims reduced facial redness from inflammatory reaction, a photoprotective effect, and reduced appearance of dilated vessels and hyperpigmentation. Carries no study figures, no sample sizes, no sequence and no peptide percentage, and links no technical data sheet.
- Lipotec patent WO2013156493A1(2012)Applicant Lipotec SA, priority April 16, 2012, status ceased. Names acetyl-Ala-Thr-Asn-Thr-OH and the amide in its peptide table and uses the free acid by name through Examples 10 to 21. Example 10, cells provoked with LL-37 at 50 micrograms per mL in quadruplicate: IL-6 at 94.65% and 92.90% of baseline for peptide at 0.1 and 0.5 mg per mL against 122.28% for LL-37 alone; IL-8 at 109.39% at 0.5 mg per mL against 142.65%. Example 18, collagenase: 100% inhibition at 10 mg per mL, 29.21% at 2 mg per mL, positive control 95.19%. Example 19, tyrosinase: 86.45% at 4 mg per mL, 76.01% at 3, 38.23% at 2, kojic acid control 85.79%. Example 20, melanocytes: melanin 45.7% of control at 0.25 mg per mL and 55.8% at 0.625 mg per mL. Example 21, photoprotection: fibroblast viability 20.03% untreated, 52.37% at 1 mg per mL, 63.25% at 10 mg per mL. Example 17, human: 20 volunteers with slight rosacea, cream twice daily for four weeks, erythema about 9.0% lower at one week and 19.2% lower at four weeks, with no control arm described. The patent does not use the INCI name or the trade name anywhere.
- COSMILE Europe ingredient record, Acetyl Tetrapeptide-40(2026)Confirms the INCI name with declared function skin conditioning and synthetic origin. Carries no CAS number and does not name its own source registry.
- FDA Global Substance Registration System search, Acetyl Tetrapeptide-40(2026)Total 0. No substance record under this name. A positive control run the same day with the same query shape returned one record for ACETYL TETRAPEPTIDE-15, UNII 6K389LE0MV, so the empty result is the registry's and not the query's.
- Circadia, Chrono-Calm Serum product page(2026)The brand's own page. Lists Acetyl Tetrapeptide-40 in the ingredient list and separately names Telangyn as the calming peptide it contains. Caprylyl glycol also appears, consistent with the Lubrizol solution as the input.
- AE.R Skinlab, RE:GEN Serum product page(2026)The brand's own page. Publishes a 24-ingredient list with Acetyl Tetrapeptide-40 at position 19. The trade name is not used.
- Personal Care Magazine, caring for sensitive skin(2012)Dated December 4, 2012, publisher Step Communications. Reports a four-week test of a cream at 2% Telangyn solution with erythematic intensity down 19.2%, skin redness down 17.7%, extent down 17.9% and roughness down 7.5%, without a sample size or a control group. The 19.2% matches the patent's human example, which is where the 20-person figure comes from.
- Premium Beauty News, Lipotec targets skin inflammation(2012)Dated July 17, 2012. Reports a 28-day in-vivo test of a 2% Telangyn cream with redness intensity down 7.5%. This conflicts with the other trade report, where 7.5% is the roughness figure and redness is 17.7%. One of the two transposed a value, so the patent is used instead of either.