Back in March I wrote about a new ingredient called tripeptide-10 citrulline. It has just started to appear in products and I recently spotted it in Isomers Skin Stack, Kinerase Extreme Lift Eye, Osmotics Blue Copper ($125 in the TIA shop) and Skin Doctors Antarctilyne Plump.

Tripeptide-10 citrulline looks promising because it mimics a molecule that regulates collagen fibers. As we get older, decorin (the molecule in question) activity declines. The new peptide, tripeptide-10 citrulline, behaves like decorin so that the collagen fibers are fooled into thinking they should still be productive.

A trial was conducted on 43 women, about half of which were given tripeptide-10 citrulline. Granted this was conducted by the manufacturer, Lipotec. Nevertheless, the results (published in the International Journal of Cosmetic Science) aren't bad with 54% showing an increase in skin suppleness. Over a two month period, it was shown to make the fibres more uniform.

The four products I found with tripeptide-10 citrulline are a bit of a motley bunch. The best is probably the Osmotics eye cream. Personally, I would be wary of trying Osmotics Blue Copper 5 Firming Eye Repair ($75 for 0.5oz) because I developed a bad reaction to an Osmotics face cream. Although, to be honest, until the onslaught of a rash, I did think I was getting very good results from Osmotics. So if you have a tougher hide, this is probably worth trying it out because, as well as T-10 citrulline, it contains another good ingredient called aldenine.

Aldenine is the result of combining tripeptide-1 with soy and wheat proteins. It is supposed
to boost production of collagen III (the type of collagen we had when we were very young) by 300% in seven days. Aldenine is manufactured by the same company as T-10 citrulline. There is also carnosine, an ingredient that is supposed to extend the Hayflick Limit (the number of times cells will reproduce and remain healthy). The second most dominant ingredient, after water, is another interesting one: pseudoalteromonas ferment. This is a strain of bacteria found in the Antarctic and supposedly having an impressive effect on collagen.

In fact, this combination of T-10 citrulline, T-1 and pseudoalteromonas ferment is marketed under the name of Trylagen, so keep an eye for that in ingredients lists as well. Indeed, the combination turns up in Skin Doctors Antarctilyne Plump ($58 for 3.50ml). Antarctilyne Plump also includes a sunscreen. The problem with this potion is that it has a lot of silicones, plus a number of known irritants, including triethanolamine (a carcinogen, according to one animal study), phenoxyethanol, perfumes.

Kinerase Extreme Lift Eye ($95 for 0.5oz) is much the same although it also includes a couple of ingredients that will have create a tightening sensation. One is pullulan, primarily used to make breath freshener strips. The other is a plant called acmella oleracea that supposedly is a muscle relaxant.

Finally, Isomers Skin Stacker ($85 for 10x) has a fair amount of silicone. It also has acetyl tetrapeptide-9, a synthetic peptide that seems to do much the same job as T-10 citrulline.