Redken's Extreme Length Shampoo with biotin strengthens damaged hair and helps hair to grow longer and stronger. Extreme Length Shampoo helps prevent breakage to promote your strongest, healthiest hair. - Reduce breakage by 81% when using the full system of Extreme Length Shampoo, Extreme Length Conditioner, and Extreme Length Leave-In Treatment- Formulated with biotin to help hair grow longer and stronger- Gently cleanses the hair- Helps promote strong hair