Well my mother has used this product a lot to surpass her white hairs but it just a matter of time when u have to apply it once again.once u apply it nice after first wash but fades as u go out and do some dusty work.uptill now my mom has no sideffects of this stuff so its safe for scalp. well it gets dry very soon so u dont have to wait for long. it comes with hand gloves and a brush to apply it on ur hairs. it contains 2 types of dyes u have mix those together and apply it n ur hair and wash after 15 mins thts it.