"There are three types of bonds in our hair: disulfide bonds, hydrogen bonds, and covalent bonds," explains medical and aesthetic dermatologist Kiran Mian, DO, FAAD. "Disulfide bonds are ...

The third type of bond, the hydrogen bond, is the most flexible, giving hair its elasticity. Unlike disulfide bonds, these are temporary bonds that can be broken down by water and quickly rebuilt.

Let’s start with the basics: Your hair is made up of more than 23 amino acids and, therefore, protein. “The amino acids have little dots that you put on top of each other, like a Lego, and that ...