Hair Revital X Kerastase Resistance Bain Volumactive Shampoo is used for treating weak hair. The weakening is caused due to many factors. The hair when exposed to sun for a longer period gets exposed to its harmful radiations which are the ultra violet rays. There are many pollutants in the air, in the water we use for washing that damage the hairs. Hard water is also responsible for breaking of hair and hair loss. Other factors like styling of hairs very often, using rods, perming, dyeing.