Retinoids inhibit matrix metalloproteinases and promote keratinocyte growth, benefiting skin, hair, and nails.

“They also have an advantage of creating keratin or promoting keratin? Right. So the keratinocytes are lower down in the skin. So keratin is a super abundant molecule as well. That's important, like collagen, for the flexibility. It's an important component of not just your skin, but your hair and your nails as well. And your retinae can promote the growth of the keratinocytes that make keratin.”