Shea Moisture’s Jamaican Black Castor Oil Strengthen & Restore Treatment Masque restores strength and resilience to damaged, brittle or chemically processed hair. After shampooing, apply a generous amount of the strengthening masque from root to end. Pay particular attention to hair ends. Comb through for even distribution. Place a plastic cap over your hair and sit under a warm dryer for 10-15 minutes. May be left on the hair for up to an hour without heat. Rinse thoroughly. Style as usual.