What it is
Collagen is a group of proteins (there are more than 25 types!) that supports bodily tissues like skin, muscles and bones. Collagen, together with Elastin, gives skin structure, flexibility and strength. The type used in cosmetics comes from animal sources or from plants derivatives that act as collagen.
What it does
When used in topical products, collagen can’t stimulate collagen synthesis. That’s because its molecules are too big to penetrate the skin which is what’s necessary to produce collagen.
Instead, collagen sits on top of the skin and moisturizes it. It is a good water-binding agent that holds moisture in and hydrates skin.
Collagen is considered to be safe. However, it can’t replace the collagen the skin lost or stimulate its production, like marketing claims imply.