A small, three amino acid (glycine-histidine-lysine or GHK) peptide that is famous for being a type I collagen fragment. The theory behind collagen-fragment peptides is that when collagen naturally breaks down in the skin, the resulting peptide fragments signal to the skin that it should get to work and create some nice, new collagen.
Adding in collagen fragment peptides, like GHK, might trick the skin into thinking that collagen has broken down and it's time to create some more. So Tripeptide-1 is believed to be able to stimulate collagen production in the skin, and more collagen means fewer wrinkles and younger looking skin. FYI; Tripeptide-1 is the same peptide that can be found in the famous Matrixyl 3000, but in Matrixyl a palmitic acid is attached to it to increase its oil solubility and thus skin penetration.
Another reason why Tripeptide-1 is especially famous is that it is not only a signal peptide but also a so-called carrier peptide that helps to stabilize and deliver copper in the skin. It has a high affinity for copper ions and likes to form a complex with them called Copper-Tripeptide-1 or GHK-Cu. GHK-Cu is a famous and well-researched peptide that does a bunch of things in the skin and we have a shiny explanation about it here.
As for Tripeptide-1 in and of itself, without a palmitic acid or copper attached to it, it goes by the trade name Kollaren and according to the manufacturer, it not only stimulates collagen but also other essential skin proteins such as fibronectin, elastin, and laminin. Kollaren is also claimed to be beneficial for acne-prone skin as it can boost tissue repair and thus help acne scars to heal faster.
Show me some proof
- Gorouhi, F., and H. I. Maibach. "Role of topical peptides in preventing or treating aged skin." International journal of cosmetic science 31.5 (2009): 327-345.
- Maquart, François-Xavier, et al. "An introduction to matrikines: extracellular matrix-derived peptides which regulate cell activity: Implication in tumor invasion." Critical reviews in oncology/hematology 49.3 (2004): 199-202.