Rainbow Henna Hair Color is 100% natural plant material–no additives, chemicals, preservatives, metallic salts or metals. Rainbow Henna coats the outside of each strand of hair. The shade of Henna is reflected through the hair while enhancing your hair's natural color. The cuticle is smoothed by Henna's sealing action, giving hair a polished look by making the light reflect off providing shine. Regular use of Henna can texturize the hair, giving it extra body--this becomes more evident with each application. Rainbow Henna color will last approximately 4 to 6 weeks but is safe to use more frequently.