Keratin: The Key to Strong, Elastic Hair – Understanding Hair Strength

The protein keratin is what gives the hair the majority of its strength and elasticity.

Keratin makes up about 90% of the hair shaft. Its structure, which includes strong disulfide bonds between amino acids, provides the hair with its resilience and ability to stretch and bounce back. The more intact and healthy the keratin structure, the stronger and more elastic the hair will be.