Research Only Cosmetic & Skin

Tripeptide-10 Citrulline

also known as: T10-C, Decorinyl (trade name), Lys-Asp-Ile-Cit-NH2

The INCI name for the active peptide in Decorinyl® — a tetrapeptide (KDI-Cit) where the charge pattern (+/−/0/+) reproduces decorin's collagen-binding motif. Separate listing from the "decorinyl" trade-name entry to make INCI-level search usable for formulators.

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

2–5 % (finished formulation, as supplied Decorinyl solution delivering ~0.01 % active) twice daily (topical)

Cosmetic concentrations. Published clinical study used a 0.01 % active-peptide liposomal formulation.

Regulatory status

Cosmetic ingredient; not a drug. INCI name: Tripeptide-10 Citrulline. Commonly encountered trade name: Decorinyl® (Lipotec / Lubrizol).

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.
[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.
[manufacturer] Lipotec / Lubrizol. "Decorinyl® (Tripeptide-10 Citrulline) technical data sheet." CAS 960531-53-7.

Related peptides

Decorinyl

The actual identity of the Lipotec "Decorinyl®" ingredient — a decorin-mimetic tetrapeptide (Lys-Asp-Ile-Cit-NH2) engineered to regulate collagen fibril diameter and uniformity in aged skin. Often confused with "Tridecapeptide-4"; the authoritative literature (Puig et al. 2008) classifies it as INCI Tripeptide-10 Citrulline.

Matrixyl

A palmitoylated pentapeptide derived from a collagen-I breakdown fragment (KTTKS) — widely used in cosmetic topicals with clinical data supporting modest reductions in fine-line depth over 12 weeks.

Argireline

A cosmetic-industry hexapeptide marketed as "topical Botox" — reduces muscle contraction signaling at the neuromuscular junction; modest but documented effects on expression-line depth.

Disclaimer

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.