That said, since keratin treatments are meant to smooth out your hair, wavy, curly, and coily hair types may benefit from them the most. There are two components to the formaldehyde-free treatment ...

A semi-permanent alternative to relaxer ... of amino acids and glyoxylic acid to temporarily loosen curly and coily hair. It’s a treatment that has to be done in-salon by a professional.

A keratin treatment is a semi-permanent hair straightening method that aims to smooth and straighten frizzy or curly hair, says Ross Kopelman, MD, a board-certified hair surgeon at Kopelman Hair ...