Collagen extract is a structural protein, typically sourced from animal tendon, skin, cartilage, or bone, that's purified for cosmetic use to isolate the pure protein. Rather than rebuilding skin's own collagen, its main role topically is as a humectant. It helps prevent transepidermal water loss, or TEWL, leaving skin looking hydrated, refreshed, and more supple.
It's also used to improve the texture of a formula itself. Depending on what a product is trying to achieve, collagen extract typically shows up at concentrations between 0.5% and 5%.
