What it is
DNA, which is short for deoxyribonucleic acid, is a molecule that holds genetic information. It is found in all cells.
What it does
Manufacturers claims DNA can fight the signs of aging by telling cells to produce more collagen, controlling inflammation and protecting skin from the sun, but so far nothing has been proved.
DNA in skincare is controversial, and not just for the lack of studies supporting its potential effectiveness. If DNA worked as claimed (and it’s highly unlikely it does when applied topically), then it would affect the genes and you don’t really want to use anything that can do that. Any product that messes with genes has to be classified as a drug, not a cosmetic, and hence be subjected to much stricter regulations, to make sure it won’t have any dangerous side effects.