Nexxus Color Assure Conditioner has been specially formulated to help extend the color vibrancy of color-treated hair. Created with our exclusive PROTEINFUSION blend this conditioner helps protect essential proteins with the hair fiber helping bring hair back to life after the coloration process. For best results use with the Nexxus Color Assure Shampoo. First apply shampoo to wet hair working it into a lather before rinsing thoroughly. Then apply the Color Assure Conditioner let rest for 3 minutes and rinse thoroughly. This conditioner can help enhance vibrancy for up to 8 weeks or 40 washes. Nexxus scientists used Proteomics studies to examine hair damage at the molecular level and found that the main cause of color loss and dullness is hair coloration.