Acetyl Tetrapeptide-15 (Skinasensyl)_Dosage, benefits & legal status
Also known as Skinasensyl, Skinasensyl LS 9749, Skinasensyl PW LS 9852, Ac-YPFF-NH2, Ac-Tyr-Pro-Phe-Phe-NH2
An acetyl-capped copy of endomorphin-2, an opioid peptide, sold by BASF as Skinasensyl to make reactive skin less easily irritated. Its only data are supplier tests published without numbers.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Acetyl Tetrapeptide-15 (Skinasensyl)?
Plain language first. The technical label stays, but it never stands alone.Overview
It is a soothing ingredient in creams, serums and cleansers for sensitive skin, including lines such as Bioderma Sensibio Tolerance+ and Dermalogica UltraCalming, so many people with reactive skin already use it. The best evidence is a supplier test in 20 volunteers: after a 0.0015% solution twice a day for 4 days, it took more capsaicin, the compound that makes chili peppers hot, to cause discomfort, but no numbers were published. It is built from an opioid peptide, yet no study shows it does anything beyond the skin, and a 2021 review found no studies of it in the scientific literature.
Acetyl tetrapeptide-15 is Ac-Tyr-Pro-Phe-Phe-NH2: endomorphin-2, an opioid peptide, with an acetyl cap on its first residue. It was introduced in 2008 as Skinasensyl by Laboratoires Sérobiologiques, then the active-ingredients business of Cognis, and is now sold by BASF; the supplier says it acts on µ-opioid receptors on skin nerve endings to cut release of the neuropeptide CGRP and raise the threshold at which skin feels discomfort. Those results come only from supplier tests described without effect sizes, no binding affinity or potency has been published for the acetylated peptide, and a 2021 review found no studies of it in the scientific literature.
What it's used for
A cosmetic ingredient in soothing creams, serums, cleansers and hair conditioners for sensitive or reactive skin, listed in 40 products on one ingredient database and more than 50 on another. Used only on the skin.
How does Acetyl Tetrapeptide-15 (Skinasensyl) work?
What it does in the body, and where.Acetyl tetrapeptide-15 is endomorphin-2, an opioid peptide, with an acetyl cap, and its supplier says it calms skin through opioid receptors on sensory nerve endings.
- 01An opioid peptide, cappedIn 1997 Zadina and colleagues reported endomorphin-1, isolated from brain, as a potent and selective natural activator of the µ-opioid receptor, and also isolated endomorphin-2 (Tyr-Pro-Phe-Phe-NH2), one residue different. Acetyl tetrapeptide-15 is endomorphin-2 with an acetyl group on its first tyrosine. No binding affinity or potency for the acetylated form has been published.
- 02Less nerve signal releasedSensory nerve cells release a signaling peptide called CGRP when stimulated. In supplier tests described by a 2021 review, cells treated for 6 hours with 0.001% of the peptide released less CGRP after stimulation with potassium chloride and capsaicin, doing better than capsazepine, a capsaicin-receptor blocker, and about as well as the calcium-channel blocker verapamil. Naloxone, an opioid-receptor blocker, weakened the effect. No percentages or p-values were published.
- 03A higher discomfort thresholdThe supplier links this to a higher threshold before skin feels discomfort, from its capsaicin test in 20 volunteers. No data show whether the peptide passes through the skin, how long it lasts there or whether any reaches the blood, and no study shows any effect beyond the skin.
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.
Supplier nerve-cell test
Supplement or cosmetic- Lab studySensory neurons were incubated for 6 hours with 0.0003% or 0.001% of the peptide, capsazepine 10 µM or verapamil 100 µM, then stimulated with potassium chloride and capsaicin.
- Lab studyThe review reports that 0.001% cut CGRP release very significantly, better than capsazepine and similar to verapamil, and that naloxone, an opioid-receptor blocker, weakened the effect.
- No dataNo percentages or p-values are given, and the data trace back to supplier marketing material.
Supplier volunteer test
Supplement or cosmetic- human-early20 volunteers, split-face and single-blind: capsaicin on the folds beside the nose set the dose that caused discomfort, then a 0.0015% solution went on one side of the face and vehicle on the other, twice daily for 4 days, before the challenge was repeated.
- human-earlyThe review reports a significant increase in the capsaicin dose that provoked discomfort, with no effect size, p-value or responder rate.
- No dataNo randomization is described, the vehicle side is the only comparison, and the review does not say the volunteers had sensitive skin; it names a different peptide as the only one tested in sensitive-skin volunteers.
Independent research
none- ReviewA 2021 review of peptides in sensitive-skin products found no studies of this compound in the scientific literature; its sources for the supplier data are a BASF web page and two trade-press articles.
- Lab studyThe only independent paper found, a 2016 chemistry study from Adam Mickiewicz University in Poland, describes a related compound, the same four-residue chain with jasmonic acid in place of the acetyl cap (JA-YPFF-NH2); its abstract reports no biological testing.
How widely it is used
Supplement or cosmetic- ReviewOf 88 facial products for sensitive skin from multinational brands, 15 (about 17%) contained peptides, 7 distinct ones; acetyl tetrapeptide-15 was the third most used, after acetyl dipeptide-1 cetyl ester and palmitoyl tripeptide-8.
- ReviewIngredient databases list it in 40 to more than 50 products, including Bioderma Sensibio Tolerance+ and Dermalogica UltraCalming Serum Concentrate; these databases are user-built and not complete.
It is correctly described as derived from endomorphin-2: it is endomorphin-2 (Tyr-Pro-Phe-Phe-NH2) with an acetyl cap. Some distributor pages give the sequence as N-acetyl-Tyr-Pro-Phe-NH2, three residues; the correct sequence has four, Ac-Tyr-Pro-Phe-Phe-NH2, as FDA's substance registry, the review and Cayman give it. A 2021 review is reported to describe supplier testing in 20 volunteers, and it does: a split-face, single-blind test with no published effect size, in volunteers the review does not describe as having sensitive skin. Its authors are reported to have found independent clinical research lacking; their wording is broader, that no studies were found in the scientific literature for this compound at all. One evidence-rating site grades it as backed by one randomized trial or several controlled studies, cites a Cosmetic Ingredient Review safety assessment and rates it safe in pregnancy; no randomized trial has been published, no such assessment was found, and no pregnancy data exist. Despite the similar names, acetyl tetrapeptide-2 and acetyl tetrapeptide-11, also on this site, are different molecules; the INCI numbers do not signal a family.
The published record
Papers and trials about Acetyl Tetrapeptide-15 (Skinasensyl)
Furthest stage reached: No clinical trial on record
Counted from Europe PMC indexing, not read by a person; a human tag can land on reviews, commentary or lab papers; clinical trial publications is the narrower count.
At a glance
Four things to know about Acetyl Tetrapeptide-15 (Skinasensyl)
Evidence
Cosmetic
Category
Skin and cosmetic
Common vial
Varies
Half-life
Not established
How much, and do you cycle it?
The range, and whether you take breaks.BASF use level not public; 0.0015% in the supplier's volunteer test (2021 review), twice daily (supplier test). Daily use Community practice
Applied daily like other cosmetic actives. The supplier's volunteer test used it twice a day for 4 days.
Not establishedNo figure
Applied to the skin. No skin-penetration, stability or blood-level data have been published, so whether any reaches the bloodstream is not known.
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-15 (Skinasensyl) is not injected
It is taken on the skin (cream or serum). A cosmetic ingredient in creams, serums, cleansers and hair conditioners. BASF's recommended use level for both Skinasensyl grades is not public, and neither is the peptide content of either grade, so the amount of peptide in a product cannot be worked out and the calculator has no range to draw. As a 2021 review describes them, the supplier's lab tests used 0.0003% and 0.001%, and its volunteer test a 0.0015% solution twice daily for 4 days; the review does not say whether these are percentages of pure peptide or of the trade grade. One reseller says its own powder, sold as Pep-Sensyl, holds 1,500 ppm peptide and lists a use rate of 0.3 to 1%; BASF has not published either figure. There is no oral or injected dose.
How do you store it?
Before mixing, and after.Room temperature, out of light. Cap it tight after each use.
Acetyl Tetrapeptide-15 (Skinasensyl) 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
- Not studied in any published trial: the only human data are a supplier test in 20 volunteers, described without numbers, and the review that reports it does not say they had sensitive skin
- Not studied by injection or by mouth: it is sold as a skin-care ingredient and as a lab reagent, and no study has looked at its effects inside the body
- Not studied in pregnancy: a pregnancy rating of safe that circulates online gives no data
- Known sensitivity to a product that contains it
Stop and get help
- Redness, burning, itching or a rash where it is applied
Common effects
- No side effects of the peptide have been reported in any published source, supplier or independent
- No tolerance results from the supplier's 4-day test in 20 volunteers have been published
- No repeated patch test, irritation or sensitization study has been published, and no Cosmetic Ingredient Review safety assessment was found
- One online rating of low irritation and allergy potential gives no data; the Cosmetic Ingredient Review assessment it lists as a source could not be found
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Acetyl Tetrapeptide-15 (Skinasensyl) approved?
And where the numbers on this page come from.Not as a medicine. Acetyl Tetrapeptide-15 (Skinasensyl) 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)
- Checked21 October 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.
- SourcesFDA GSRS substance record, acetyl tetrapeptide-15 (UNII 6K389LE0MV)Resende DISP et al., Pharmaceuticals 2021;14:702Crossref reference list for Resende et al. 2021Zadina JE et al., Nature 1997;386:499-502SpecialChem, Skinasensyl LS 9749 (BASF)SpecialChem, Skinasensyl PW LS 9852 (BASF)Cosmetics & Toiletries, Tetrapeptide for Neurosensitive Skin (December 9, 2008)Happi, Supplier's Corner (December 2, 2008)Personal Care Magazine (January 26, 2009)Cayman Chemical, acetyl tetrapeptide-15 acetate (item 35180)INCIDecoder, acetyl tetrapeptide-15Skinsort, acetyl tetrapeptide-15DailyMed, search for UNII 6K389LE0MV
What has happened recently
A cosmetic ingredient, not a drug, with no drug approval, designation, IND or clinical-trial registration found anywhere. Ingredient databases citing the EU cosmetic ingredient database (CosIng) give it ID 85459 with the function skin conditioning; whether CosIng lists any restriction is not established. FDA's substance registry gives it UNII 6K389LE0MV and lists the brand name Skinasensyl, and it appears in 12 labels on DailyMed, all over-the-counter sunscreens or tinted SPF creams in which sunscreen filters are the active ingredients. No Cosmetic Ingredient Review safety assessment was found. Laboratoires Sérobiologiques, the active-ingredients business of Cognis Care Chemicals, launched it with trade-press coverage in December 2008 in two grades: a liquid, Skinasensyl LS 9749 (in water, glycerin and coco-glucoside, preserved with sorbic acid), and a preservative-free powder, Skinasensyl PW LS 9852 (in mannitol and sodium citrate). Both grades are now sold by BASF. Research-grade material is sold as a lab reagent, not as a cosmetic.
You can compare this against the whole library, or read how to check a seller.
What else is like Acetyl Tetrapeptide-15 (Skinasensyl)?
Others in Skin and cosmetic, side by side.If you're weighing Acetyl Tetrapeptide-15 (Skinasensyl), it's worth reading Acetyl Tetrapeptide-2 (Thymulen 4), Acetyl Tetrapeptide-3, and Acetyl Tetrapeptide-5 (Eyeseryl) in the same class.
An acetyl-capped copy of endomorphin-2, an opioid peptide, sold by BASF as Skinasensyl to make reactive skin less easily irritated. Its only data are supplier tests published without numbers.
- Dose
- BASF use level not public; 0.0015% in the supplier's volunteer test (2021 review)
- How often
- Twice daily (supplier test)
A four-residue piece of the thymus hormone thymopoietin, close kin to thymopentin, sold by two suppliers with two different stories. Its only independent study was done in cultured skin cells.
- Dose
- 2% Uplevity solution in a cream or serum (supplier), about 10 ppm peptide if the solution is 0.05% peptide
- How often
- Twice daily (supplier test)
A hair peptide sold for thinning, with evidence that mostly belongs to a combination product.
- Dose
- Serum or scalp treatment, 0.1 to 5%
- How often
- Daily
A topical peptide aimed at under-eye puffiness rather than lines.
- 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
- FDA GSRS substance record, acetyl tetrapeptide-15 (UNII 6K389LE0MV)(2026)Ac-Tyr-Pro-Phe-Phe-NH2 with all four stereocenters defined as L; C34H39N5O6, MW 613.7047; CAS 928007-64-1; brand name Skinasensyl.
- Resende DISP et al., Pharmaceuticals 2021;14:702(2021)Third most-used of 7 peptides found in 88 facial products for sensitive skin. Describes the supplier's CGRP cell test and 20-volunteer split-face capsaicin test without effect sizes, and says no studies were found in the scientific literature for this compound.
- Crossref reference list for Resende et al. 2021(2021)The review's sources for the supplier test data are a BASF web page and two trade-press articles, not peer-reviewed reports; the section also cites a general paper on the capsaicin receptor and a 2016 chemistry paper.
- Zadina JE et al., Nature 1997;386:499-502(1997)Endomorphin-1 (Tyr-Pro-Trp-Phe-NH2), isolated from brain, is a potent and selective µ-opioid receptor agonist; endomorphin-2 (Tyr-Pro-Phe-Phe-NH2) differs by one residue.
- SpecialChem, Skinasensyl LS 9749 (BASF)(2020)Liquid grade: water, glycerin, coco-glucoside and acetyl tetrapeptide-15, preserved with sorbic acid; the use level is shown only after login.
- SpecialChem, Skinasensyl PW LS 9852 (BASF)(2023)Powder grade: mannitol, sodium citrate and acetyl tetrapeptide-15; preservative-free and listed as vegan.
- Cosmetics & Toiletries, Tetrapeptide for Neurosensitive Skin (December 9, 2008)(2008)Launch by Laboratoires Sérobiologiques in two grades; says it lowers CGRP release; recommends it for sensitive-skin, anti-stress, cosmeceutical and men's care products; no numbers.
- Happi, Supplier's Corner (December 2, 2008)(2008)Laboratoires Sérobiologiques launch; claims a higher tolerance threshold and says it was tested on a mixed panel for men's care; no numbers.
- Personal Care Magazine (January 26, 2009)(2009)Laboratoires Sérobiologiques is part of Cognis; a 4-day, twice-daily pre-treatment made skin more tolerant to capsaicin, with an immediate soothing effect on temperature tolerance; no numbers.
- Cayman Chemical, acetyl tetrapeptide-15 acetate (item 35180)(2026)N-acetyl-L-Tyr-L-Pro-L-Phe-L-Phe-NH2, purity at least 95%, described as a peptide derivative of endomorphin 2; sold as a research reagent.
- INCIDecoder, acetyl tetrapeptide-15(2026)More than 50 products, including Bioderma Sensibio Tolerance+, Dermalogica UltraCalming Serum Concentrate and Rilastil Soothing Micellar Solution; the database is user-built.
- Skinsort, acetyl tetrapeptide-15(2026)Found in 40 products; CosIng ID 85459, function skin conditioning.
- DailyMed, search for UNII 6K389LE0MV(2026)12 labels, all sunscreens or tinted SPF creams with sunscreen filters as the active ingredients.
Beyond these, 1 records are indexed. Browse the records