Collagen

Collagen is a big structural protein that your body uses to keep skin firm and bouncy. Despite the marketing, topically applied collagen doesn't "refill" the collagen in your skin.

The molecule is too big to pass through your skin barrier so intact Collagen physically can't get past the surface.

What it actually does in your skincare is work as a humectant and film-former: it binds water, lays down a light moisturizing film, and reduces water loss from the surface. This helps make skin feel smoother and temporarily plumper.

This ingredient has been found safe for use in cosmetics with clinical studies showing no irritation, sensitization, or phototoxicity. It's typically used at low concentrations (often a fraction of a percent up to a few percent).

Collagen will not increase sun sensitivity, but you should always wear sunscreen during the day.

Learn more about hydrolyzed collagen or soluble collagen.