Trade name Matrixyl, a fatty acid mixed with amino acids. The only research showing this has any significance for skin was carried out by the ingredient manufacturer, Sederma. In their research, three different “half-face” studies with a total of about 45 participants showed it to be better than a retinol or vitamin C product (Source: Journal of Cosmetic Science, January–February 2001, pages 77–78). Without independent substantiation, however, there is no way to know how accurate this company-funded research is. Further, according to Sederma’s research, the recommended concentration for this ingredient is 3% to 5% and there are few, if any, lines that include more than just a trace amount in their products.