EcoColors Haircolor is a permanent haircolor and is not a henna based haircolor. Th color lasts until it grows out. The average application wait is about 6 weeks. Permanent haircolor may fade more quickly on porous hair or with use of strong shampoos. We recommend you use Pureology shampoo and conditioner(sold in Salons). Always do an allergy test and a strand test before applying any new color to your entire head.