What is Tripeptide-10 citrulline?
Tripeptide-10 citrulline was designed to copy the binding sites of decorin, a protein that helps arrange collagen fibres as skin ages.
Its INCI name says tripeptide, but the 2008 paper describes the molecule as a tetrapeptide. Labels use the INCI name.
How it is thought to work
In the 2008 lab work, it was the best of several designed candidates at regulating collagen fibrillogenesis (how collagen fibres assemble). The fibres it produced were thinner and more uniform.
The authors describe a focus on the quality of collagen fibres rather than the amount. Human results on that point are limited to the one small trial below.
What the studies show
Every record below was checked against the paper. Where a result is from cells, animals or a combination product, the entry says so.
Puig A, et al. Int J Cosmet Sci. 2008;30(2):97–104. (opens in a new tab)
Industry-authored
Design. In vitro collagen fibrillogenesis assay, electron microscopy and skin organ culture. Authors are from Lipotec, the company that makes the peptide.
Finding. Among designed candidates, tripeptide-10 citrulline gave the best result, making collagen fibres thinner and more uniform in vitro.
Raikou V, et al. J Cosmet Dermatol. 2017;16(2):271–278. (opens in a new tab)
Design. Randomised controlled trial in 24 healthy volunteers for 60 days. Four groups: the two peptides together, tripeptide-10 citrulline alone, acetyl hexapeptide-3 alone, and neither.
Finding. The authors report clinical evidence of antiwrinkle efficacy for tripeptide-10 citrulline, with a possible effect on water loss. How the two peptides work together was not clear.
How it is used
Found in anti-wrinkle creams and serums, often alongside acetyl hexapeptide-3 and other peptides. Check the full ingredient list.
Concentrations in products are not standardised and are often not disclosed.
Safety
The 2017 trial did not report side effects in its abstract. The evidence is small, so it does not establish long-term tolerance.
Patch-test a new product first, especially if your skin is sensitive.
Talk to a doctor, dermatologist or pharmacist before starting a new active, especially if you are pregnant, have a skin condition, or use prescription treatments.
Questions
Is tripeptide-10 citrulline a tripeptide or a tetrapeptide?
The INCI name says tripeptide. The 2008 paper describes it as a tetrapeptide. Product labels use the INCI name, so that is the one to search for.
Does it work on its own?
One small trial tested it alone and found effects on skin texture and water loss at some time points. Its best evidence is still limited to 24 volunteers.