Medically reviewed by William Truswell, MD Collagen is a structural protein found in tissues in skin, hair, nails, cartilage, bones, and tendons. By working with other substances, such as elastin and ...

Claiming to firm your skin, reduce the appearance of fine lines and improve radiance, as well as fortifying your hair and nails, it's no surprise collagen sales are still steadily on the rise.

there are a few things you should know about what this supplement is and how it’s made before you invest. Collagen is made by the human body. It’s a protein found in skin, hair and nails to ...