Acetyl Tetrapeptide-11_Dosage, benefits & legal status
Also known as Syniorage, AcTP11
A topical cosmetic peptide sold as Syniorage, claimed to firm mature skin by raising syndecan-1 and collagen XVII.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Acetyl Tetrapeptide-11?
Plain language first. The technical label stays, but it never stands alone.Overview
It is a skin-care ingredient that the supplier says raises syndecan-1 in the outer skin and collagen XVII where the skin layers join. A supplier study in 19 women aged 60 to 70 found firmness and elasticity improved 5 to 10% more than with placebo cream. No independent study was found.
Acetyl tetrapeptide-11 is Ac-Pro-Pro-Tyr-Leu, four amino acids taken from the pig antimicrobial peptide PR-39, with an acetyl cap. Laboratoires Serobiologiques, then part of Cognis, developed it, and BASF now sells it as Syniorage.
What it's used for
A cosmetic peptide in firming serums and creams for mature skin. Supplier data only; about 13.5 ppm was used in its clinical test.
How does Acetyl Tetrapeptide-11 work?
What it does in the body, and where.Acetyl tetrapeptide-11 is four residues from PR-39, a pig antimicrobial peptide that appears during wound healing and switches on syndecan-1.
- 01Syndecan-1 (supplier)In a reconstructed skin model, 2.6 mcg/mL for 9 days raised syndecan-1 by 38%. Syndecan-1 helps hold the outer skin cells together and falls with age, according to BASF.
- 02Collagen XVII (supplier)In skin cells it raised collagen XVII gene expression by 18% in 2 days, and BASF reports a 185% protein rise in a separate assay. These are different measures. Collagen XVII anchors the outer skin to the layer beneath.
- 03In people (supplier)19 women aged 60 to 70 used a 13.5 ppm cream twice daily for 56 days; torquemeter firmness and elasticity improved 5 to 10% more than with placebo cream. No independent study was found.
Where this compound is thought to act.
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 lab data
Supplement or cosmetic- Lab studySyndecan-1 rose 38% in a reconstructed skin model after 9 days; collagen XVII gene expression rose 18% in skin cells after 2 days.
- No dataOne supplier assay prints the dose in mg/mL where the others use mcg/mL, a likely unit error.
Supplier human study
Supplement or cosmetic- Human trial19 women aged 60 to 70, 56 days, against placebo cream: firmness and elasticity improved 5 to 10% more. Randomisation, blinding and p-values for the placebo comparison were not published.
- No dataNo independent study of acetyl tetrapeptide-11 was found.
Some vendors describe the unacetylated tetrapeptide-11 (Pro-Pro-Tyr-Leu) with the acetylated version's claims; the supplier data are for the acetylated form. Claims about collagen I, III and IV, laminin, acne and hair growth have no supplier data behind them. A 2017 review says the supplier study showed thicker skin; the supplier measured firmness and elasticity, not thickness. One retailer rates it as supported by independent studies; none was found. The collagen XVII figure is +18% (gene expression) or +185% (protein), from different assays.
The published record
0
Papers and trials about Acetyl Tetrapeptide-11
Europe PMC was searched on 13 October 2026 and returned nothing.
Counted from Europe PMC indexing, not read by a person.
At a glance
Four things to know about Acetyl Tetrapeptide-11
Evidence
Cosmetic
Category
Skin and cosmetic
Common vial
Varies
Half-life
Not applicable (topical)
How much, and do you cycle it?
The range, and whether you take breaks.Serum or cream, per product, daily. Daily use Community practice
Applied daily, usually twice, like other cosmetic actives. The supplier study ran 56 days.
Not applicable (topical)No figure
Applied to the skin. No skin penetration or blood-level data have been published.
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-11 is not injected
It is taken on the skin (cream or serum). The supplier's clinical test used a cream with 3% of the trade product, equal to 13.5 ppm (0.00135%) of the peptide. BASF's Replexium blends work out to 10.5 to 16.5 ppm in a finished product, and one DIY vendor's 1 to 3% use rate of a 1,500 ppm powder gives 15 to 45 ppm. Some bulk sellers suggest 100 to 1,000 ppm, far above anything tested. Applied as a cosmetic; there is no injected dose.
How do you store it?
Before mixing, and after.Room temperature, out of light. Cap it tight after each use.
Acetyl Tetrapeptide-11 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
- Injecting it: it is sold and tested only as a skin-care ingredient
- Known sensitivity to a product that contains it
Stop and get help
- Redness, burning or a rash where it is applied
Common effects
- No irritation or sensitisation data have been published; BASF describes 'excellent tolerance' without data
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Acetyl Tetrapeptide-11 approved?
And where the numbers on this page come from.Not as a medicine. Acetyl Tetrapeptide-11 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)
- Checked12 October 2026
- DoseFrom product labeling and published use.
- Vial sizeFrom what vendors typically list; not a recommendation.
- SourcesCosmetics & Toiletries, Premium tetrapeptide targets epidermis cohesion (supplier-authored)BASF, Syniorage PW LS 9847 product pageBASF, Replexium webinar (May 2018)US8044028B2, Oligopeptides and their use in cosmeticsSchagen SK, Cosmetics 2017;4:16 (review)Cayman Chemical, acetyl tetrapeptide-11 product page
What has happened recently
A cosmetic ingredient, not a drug. Listed in the EU under the INCI name Acetyl Tetrapeptide-11 with a skin-conditioning function; BASF states compliance with the EU Cosmetics Regulation and China's IECIC. Covered by Cognis patent US8044028 (priority 2004), now assigned to BASF. No CIR or SCCS safety assessment was found.
You can compare this against the whole library, or read how to check a seller.
What else is like Acetyl Tetrapeptide-11?
Others in Skin and cosmetic, side by side.If you're weighing Acetyl Tetrapeptide-11, it's worth reading Acetyl Tetrapeptide-3, Acetyl Tetrapeptide-5 (Eyeseryl), and Biotinoyl Tripeptide-1 in the same class.
A topical cosmetic peptide sold as Syniorage, claimed to firm mature skin by raising syndecan-1 and collagen XVII.
- Dose
- Serum or cream, per product
- How often
- Daily
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
GHK with a biotin tail, sold for hair and lashes rather than skin.
- Dose
- Serum, 2 to 6 ppm typical in a finished 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
- Cosmetics & Toiletries, Premium tetrapeptide targets epidermis cohesion (supplier-authored)(2013)N-acetyl-Pro-Pro-Tyr-Leu from cathelicidin PR-39. Syndecan-1 +38% in reconstructed skin; COL17A1 expression +18%. 19 women aged 60 to 70, 56 days twice daily at 13.5 ppm: firmness and elasticity 5 to 10% better than placebo cream.
- BASF, Syniorage PW LS 9847 product page(2026)INCI Acetyl Tetrapeptide-11, Mannitol; firming agent; claims syndecan-1 and collagen XVII stimulation; tested on volunteers over 60.
- BASF, Replexium webinar (May 2018)(2018)N-Acetyl-Pro-Pro-Tyr-Leu, MW 530.6; collagen XVII +185% by immunocytochemistry; Replexium blends of acetyl tetrapeptide-11 and -9 with peptide levels given in ppm.
- US8044028B2, Oligopeptides and their use in cosmetics(2011)Cognis France patent, priority 18 October 2004; Pro-Pro-Tyr-Leu is the preferred tetrapeptide, preferably acetylated, for stimulating syndecan-1.
- Schagen SK, Cosmetics 2017;4:16 (review)(2017)Lists acetyl tetrapeptide-11 among signalling peptides; restates the supplier data.
- Cayman Chemical, acetyl tetrapeptide-11 product page(2026)Ac-PPYL-OH, CAS 928006-88-6, C27H38N4O7, MW 530.6; research use only. (Vendor.)