Tripeptide-10 Citrulline
The INCI name for the active peptide in Decorinyl® — a tetrapeptide (KDI-Cit) whose charge pattern (+/−/0/+) reproduces decorin's collagen-binding motif. Decorinyl is the trade name of this molecule; both names lead to this entry.
A synthetic tetrapeptide (Lys-Asp-Ile-Citrulline-NH2, CAS 960531-53-7) modeled on decorin's collagen-fibril-binding motif; the INCI-registered active in Lipotec's Decorinyl® cosmetic ingredient. The "Tripeptide-10" INCI stem names the three proteinogenic residues, with the C-terminal L-citrulline called out separately because citrulline (a ureido amino acid) is not one of the standard twenty. Primary published evidence comes from Puig et al. 2008 (Int J Cosmet Sci), which describes the design rationale and a placebo-controlled trial of a 0.01 % formulation showing a 54 % increase in skin suppleness at 28 days. A separate randomised-controlled study (Raikou et al. 2017) examined the combination with Acetyl Hexapeptide-3 (Argireline). Cosmetic ingredient only; not a drug.
Mechanism of action
Mimics the collagen-binding region of decorin, a small leucine-rich proteoglycan (SLRP) that decorates the surface of type I collagen fibrils and regulates lateral fusion and fibril diameter during fibrillogenesis. The four-residue KDIC motif preserves the +/−/0/+ charge pattern of the native decorin binding sequence (with C-terminal citrulline replacing the native neutral residue for stability) and is proposed to occupy the same fibril surface site. In aged and photoaged skin, endogenous decorin is progressively truncated and loses regulatory activity; Tripeptide-10 Citrulline is proposed to partially compensate by re-establishing surface regulation. In-vitro fibrillogenesis assays show narrower, more uniform fibrils in treated samples. Cosmetic clinical evidence is limited but available (Puig 2008, Raikou 2017). Commonly co-formulated with Tripeptide-1 in Trylagen™ or with Acetyl Hexapeptide-8 in wrinkle formulations.
Primary uses
- Topical cosmetic anti-aging formulations (collagen-quality / fibril organization)
Typical dosing
The concentrations in circulation come from the ingredient's supplier, and a seller's figure is not a source on this site; no study in the sources read sets one.
Regulatory status
Cosmetic ingredient; not a drug. INCI name: Tripeptide-10 Citrulline. Commonly encountered trade name: Decorinyl® (Lipotec / Lubrizol).
Status as of this entry's last review, April 19, 2026. Approvals, compounding rules and sport rules change; the regulatory tracker is checked more often.
What we checked
Tripeptide-10 citrulline, sold as Decorinyl, is a tetrapeptide designed to mimic how decorin binds collagen. Its developers' laboratory paper and one small human study exist; this section records what can be checked.
Identity, computed
| Sequence | Not established |
The dataset gives Lys-Asp-Ile-Cit-NH2. The calculator does not model citrulline, so the dataset's formula is not recomputed here.
Regulatory status, read October 5, 2026
Drugs@FDA: 0 records for “tripeptide-10 citrulline”. EMA medicines list: 0 records for “tripeptide-10 citrulline”. Run for semaglutide, the same queries return 6 and 5 records (and the registry search 84 trials), so a zero here is an absence, not a broken search. Not named on the WADA 2026 and 2027 Prohibited Lists. As a substance with no current approval for human therapeutic use, it falls under section S0 (non-approved substances), which is prohibited at all times; the lists were read on September 27, 2026.
What the maker or sellers claim
Claim, from the ingredient's maker and cosmetic sellers: It organises collagen fibres for firmer, smoother skin. Evidence is a laboratory paper and one 24-person study.
About decorin
Decorin is a skin protein that binds collagen and regulates how its fibres form. The developers' 2008 paper, cited in References, engineered tetrapeptides from decorin's binding sites. A 2017 study in 24 volunteers, also cited, compared this peptide with acetyl hexapeptide-3 and a combination over 60 days, reporting changes in skin-surface measures between some groups; with four groups of about six people, it is a very small study.
What we looked for and did not find
No adequately sized human trial, no registry record and no drug application.
| Source | Query | Results, October 5, 2026 | What it was |
|---|---|---|---|
| PubMed | tripeptide-10 citrulline | 2 | |
| PubMed | Decorinyl | 0 | |
| ClinicalTrials.gov | tripeptide-10 citrulline | 0 | |
| Drugs@FDA (openFDA) | tripeptide-10 citrulline | 0 | |
| EMA medicines list | tripeptide-10 citrulline | 0 |
References
- [pubmed] Puig A, García Antón J, Mangues M. "A new decorin-like tetrapeptide for optimal organization of collagen fibres." Int J Cosmet Sci, 2008;30(2):97-104. PMID: 18377618.
- [pubmed] Raikou V, Varvaresou A, Panderi I, Papageorgiou E. "The efficacy study of the combination of tripeptide-10-citrulline and acetyl hexapeptide-3. A prospective, randomized controlled study." J Cosmet Dermatol, 2017;16(2):271-278. PMID: 28150423.
- [manufacturer] Lipotec / Lubrizol. "Decorinyl® (Tripeptide-10 Citrulline) technical data sheet." CAS 960531-53-7.
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This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.