Tripeptide-10 Citrulline (Decorinyl)_Dosage, benefits & legal status
Also known as Decorinyl, Tripeptide-10 Citrulline, tripeptide 10 citrulline, T10-C, Lys-Asp-Ile-Cit-NH2, KDI-Cit-NH2
A four-residue mimic of decorin, the skin protein that keeps collagen fibrils evenly sized, made by Lipotec and now sold by Lubrizol. In the one independent trial it was not significantly better than placebo on its own.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Tripeptide-10 Citrulline (Decorinyl)?
Plain language first. The technical label stays, but it never stands alone.Overview
It is an anti-aging ingredient in serums and creams that promises suppler skin by tidying up collagen rather than making more of it. In the one independent study, 24 women split into four groups used creams twice daily for 60 days: roughness fell 12.2% with the peptide alone against a 2.7% rise on placebo, but the difference was not statistically significant. Its other human figures, such as a 54% gain in suppleness, come from the supplier or trade press and could not be checked.
Tripeptide-10 citrulline is a synthetic tetrapeptide, Lys-Asp-Ile-citrulline with an amidated end, designed by Lipotec to mimic the collagen-binding regions of decorin and now sold by Lubrizol as Decorinyl. It is designed to bind type I collagen fibrils and, in company lab and reconstructed-skin work, made them thinner and more uniform; it is pitched as improving collagen quality rather than quantity. It is supplied as a liposomal suspension with 0.2% peptide, used at 5% in finished products.
What it's used for
A cosmetic ingredient in anti-aging serums and creams aimed at suppleness and wrinkles, listed in about 77 products. Used only on the skin.
How does Tripeptide-10 Citrulline (Decorinyl) work?
What it does in the body, and where.Tripeptide-10 citrulline was designed to imitate decorin, a skin protein that keeps collagen fibrils evenly sized.
- 01What decorin doesDecorin, a small proteoglycan, binds collagen through its core protein and limits excess bundling, keeping fibrils uniform. Lipotec says functional decorin declines with age, disrupting the fibers and lowering the skin's tensile strength.
- 02A designed mimicLipotec screened a focused library of several four-residue candidates modeled on decorin's collagen-binding regions and picked this one. It is a designed mimic, not a copy: the patent says the sequence is not found in native decorin and that citrulline is essential.
- 03Quality, not quantityIn a lab collagen assay and in reconstructed skin it gave thinner, more uniform fibrils; a patent example reports a 15.1% smaller mean diameter after 14 days. It is thought to work by binding fibrils, with no known receptor and no published binding measurements; the company does not claim it makes more collagen.
A schematic of the compound's mechanism, not a diagnostic image.
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.
Alone, against placebo
tested-and-failed- Human trial24 women, four groups, 60 days: roughness fell 12.2% (cR2) and 8.8% (cR3) with 5% Decorinyl alone, against rises of 2.7% and 2.6% on placebo; neither difference was significant.
- Human trialThe only significant difference from placebo, at day 20, was a smaller rise in cR3 roughness (5.8% against 7.2%).
- No dataGroup sizes, blinding, ethics approval and the statistical test were not reported, and some table values contradict each other.
Combined with Argireline
Early research- Human trialArgireline 10% plus Decorinyl 5% cut cR2 roughness 12.8% by day 60, significantly more than placebo (P=.025); Argireline alone cut it 11.7%.
- Human trialWater loss through the skin fell only with Argireline alone.
- No dataNo test for synergy was reported, and the authors said how the two peptides might act together was unclear.
Company lab and skin-model work
Early research- Lab studyIn Lipotec's 2008 collagen fibril-formation screen it gave the best results of several decorin-like candidates, producing thinner, more uniform fibrils.
- Lab studyIn reconstructed skin at 0.1 mg/mL for 14 days, mean fibril diameter was 15.1% smaller than untreated, with no replicates or statistics given.
- No dataThe diameters as printed (6.825 against 5.791 nm) are about 10 times smaller than normal skin fibrils, so the units may be misprinted.
Supplier and trade-press human claims
Supplement or cosmetic- Human trialA 2008 trade report says a 0.01% cream made collagen fibers more uniform in 3 volunteers, and that 22 women using it had a 54% increase in suppleness against 21 on placebo. The method, duration and statistics could not be checked.
- No dataLubrizol reports a 50% rise in suppleness in 1 month, without published methods (supplier data).
The name says tripeptide, but it has four amino acids: the EU ingredient definition calls it the reaction product of citrulline and tripeptide-10. Plain tripeptide-10 is a different ingredient, Lys-Asp-Ile (CAS 515835-71-9), yet some lab vendors sell this compound (CAS 960531-53-7) under that name, and one tripeptide-10 datasheet cites the 2017 study of this peptide. It is often called a signal peptide; it is designed to bind collagen fibrils, not to signal to cells. The often-quoted 54% gain in suppleness comes from 2008 trade press on a company test of 22 women against 21 on placebo; Lubrizol now says 50% in a month. Neither figure can be checked. The 2017 study is often reported as showing it works, and its authors concluded so, but the peptide alone did not differ significantly from placebo at day 60; its one significant result against placebo, at day 20, was a smaller rise in roughness (5.8% against 7.2%). That arm used 5% Decorinyl, almost certainly the commercial suspension (about 0.01% peptide) rather than pure peptide, though the paper does not say so outright. It is also reported that no independent human study exists; the 2017 study was academic, though a distributor supplied the peptides. A 2020 review calls the Argireline combination synergistic, but no synergy test was run. Lubrizol's 98.02% natural-origin figure reflects the water carrier; the peptide is synthetic. The 2017 study names Argireline acetyl hexapeptide-3, the same product listed on this site as acetyl hexapeptide-8.
The published record
Papers and trials about Tripeptide-10 Citrulline (Decorinyl)
2 papers tagged human · 2 not reviews or lab · 1 clinical trial publications
Furthest stage reached: Published trials only, 1 clinical trial publication, no phased trial registered
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 Tripeptide-10 Citrulline (Decorinyl)
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.About 0.01% peptide in a cream or serum, as 5% Decorinyl (supplier), twice daily (2017 study). Daily use Community practice
Applied daily like other cosmetic actives. The 2017 study used it twice a day for 60 days.
Not establishedNo figure
Applied to the skin. No skin-penetration, absorption, stability or blood-level data have been published; supplier copy says the liposome carrier improves penetration and stability, without data.
You can compare this against the whole library to see where it sits.
What does it cost?
Typical dose and cost, in plain numbers.Tripeptide-10 Citrulline (Decorinyl) is not injected
It is taken on the skin (cream or serum). A leave-on cosmetic ingredient in creams and serums. Lubrizol supplies Decorinyl as a suspension (a reseller describes it as liposomal) containing 0.2% tripeptide-10 citrulline and recommends 5% of the suspension in a finished product, about 0.01% (100 ppm) of the peptide itself. The 2017 study used 5% Decorinyl twice daily for 60 days; the paper does not say whether 5% meant the suspension or pure peptide, though it matches the supplier's suspension level. No human study shows the isolated peptide works: in that study the arm using it alone was not significantly better than placebo. 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.
Tripeptide-10 Citrulline (Decorinyl) 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 men, or in women under 30 or over 60: the one independent study enrolled healthy women aged 30 to 60
- Known sensitivity to a product that contains it
Stop and get help
- Redness, burning, itching or a rash where it is applied
Common effects
- In the 2017 study of 24 women over 60 days, no one in any group reported warmth, stinging, redness, peeling, itching or eye irritation
- Dryness was reported only in the placebo group
- Water loss through the skin rose with the peptide alone, with the combination and with placebo, and fell only with Argireline alone; the day-60 changes were not significant
- No published repeated patch test, sensitization or irritation study was found, and no Cosmetic Ingredient Review safety assessment was found
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Tripeptide-10 Citrulline (Decorinyl) approved?
And where the numbers on this page come from.Not as a medicine. Tripeptide-10 Citrulline (Decorinyl) 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)
- Checked17 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, tripeptide-10 citrulline (UNII 2732R0E76W)Puig A et al., International Journal of Cosmetic Science 2008;30:97-104CosmeticsDesign-Europe, March 18, 2008 (trade report)Raikou V et al., Journal of Cosmetic Dermatology 2017;16:271-278Lubrizol, Decorinyl functional ingredientLubrizol, Decorinyl technical data on KnowdeLipotec patent application US 2013/0309281Google Patents, US9393186B2Lubrizol signs agreement to acquire Lipotec (ACN Newswire)DailyMed, search for UNII 2732R0E76WSkinsort, tripeptide-10 citrullineCayman Chemical, tripeptide-10 citrulline (trifluoroacetate salt)Errante et al., Frontiers in Chemistry 2020;8:572923 (review)MedChemExpress, tripeptide-10 datasheet (HY-P5262)
What has happened recently
A cosmetic ingredient, not a drug, with no drug application on record. Listed in the EU cosmetic ingredient database (CosIng, ID 83256) with the single function skin conditioning; no restriction was reported by the databases that mirror it. It appears as an inactive ingredient in 5 over-the-counter drug-cosmetic labels on DailyMed, several of them sunscreens. Lubrizol states it is China compliant (supplier data). No Cosmetic Ingredient Review safety assessment was found. Lipotec (Gavà, Spain) filed its patent on March 30, 2007, with priority from March 31, 2006; US 9,393,186 was granted on July 19, 2016. Lubrizol announced an agreement to buy Lipotec on June 20, 2012, and now sells the peptide as Decorinyl and inside its Trylagen PCB blend. Research-grade material is sold as a lab reagent not for human use.
You can compare this against the whole library, or read how to check a seller.
What else is like Tripeptide-10 Citrulline (Decorinyl)?
Others in Skin and cosmetic, side by side.If you're weighing Tripeptide-10 Citrulline (Decorinyl), it's worth reading GHK-Cu, Melanotan I (Afamelanotide), and SNAP-8 (Acetyl Octapeptide-3) in the same class.
A four-residue mimic of decorin, the skin protein that keeps collagen fibrils evenly sized, made by Lipotec and now sold by Lubrizol. In the one independent trial it was not significantly better than placebo on its own.
- Dose
- About 0.01% peptide in a cream or serum, as 5% Decorinyl (supplier)
- How often
- Twice daily (2017 study)
A copper peptide used in skincare and also sold in vials for injection, where far less has been studied.
- Dose
- 0.5 up to 2 mg per day injected (community practice). On the skin: per product
- How often
- Daily
A tanning peptide. The FDA-approved version is an implant for a rare sun-pain condition.
- Dose
- 0.5 up to 1 mg per day (loading phase)
- How often
- Daily then weekly
A stronger topical wrinkle-smoothing peptide for forehead and eye 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, tripeptide-10 citrulline (UNII 2732R0E76W)(2026)H-Lys-Asp-Ile-Cit-NH2 with defined stereochemistry; C22H42N8O7, MW 530.62; CAS 960531-53-7; brand name Decorinyl.
- Puig A et al., International Journal of Cosmetic Science 2008;30:97-104(2008)All three authors from Lipotec. A decorin-like tetrapeptide screen in a collagen fibril-formation assay; this peptide gave the best results, with thinner, more uniform fibers. The abstract gives no human numbers.
- CosmeticsDesign-Europe, March 18, 2008 (trade report)(2008)Reports a 0.01% formulation tested in 3 volunteers and a 54% increase in suppleness in 22 women against 21 on placebo. Not checked against the full paper.
- Raikou V et al., Journal of Cosmetic Dermatology 2017;16:271-278(2017)24 women aged 30 to 60, four groups, twice daily for 60 days. The peptide alone did not differ significantly from placebo at day 60; no irritation reported in any group.
- Lubrizol, Decorinyl functional ingredient(2026)Ingredient list, 5% use level and supplier claims such as a 50% rise in suppleness in 1 month (supplier data).
- Lubrizol, Decorinyl technical data on Knowde(2026)The suspension contains 0.2% tripeptide-10 citrulline; recommended use 5%.
- Lipotec patent application US 2013/0309281(2013)Lys-Asp-X-Cit family; citrulline essential; sequences not found in native decorin. Reconstructed skin at 0.1 mg/mL for 14 days: mean fibril diameter 15.1% smaller than untreated.
- Google Patents, US9393186B2(2016)Granted July 19, 2016 to Lipotec; priority March 31, 2006.
- Lubrizol signs agreement to acquire Lipotec (ACN Newswire)(2012)Agreement announced June 20, 2012.
- DailyMed, search for UNII 2732R0E76W(2026)Listed as an inactive ingredient in 5 over-the-counter drug-cosmetic labels.
- Skinsort, tripeptide-10 citrulline(2026)CosIng ID 83256, function skin conditioning; found in 77 products.
- Cayman Chemical, tripeptide-10 citrulline (trifluoroacetate salt)(2026)Lys-Asp-Ile-Cit-NH2 as a lab reagent; cites 0.01% (w/v) in a synthetic human skin model; not for human or veterinary use.
- Errante et al., Frontiers in Chemistry 2020;8:572923 (review)(2020)Calls the Argireline combination synergistic; the 2017 study reported no test for synergy.
- MedChemExpress, tripeptide-10 datasheet (HY-P5262)(2026)Tripeptide-10 is a different compound, Lys-Asp-Ile, CAS 515835-71-9, MW 374.43; the sheet cites the 2017 study of tripeptide-10 citrulline.
Beyond these, 2 records are indexed. Browse the records