A leave-in hair treatment to reverse chemical and physical damage to hair. This mask has been formulated to work without being rinsed out. First, wash your hair as normal, then towel dry gently but thoroughly. Then, dispense one pump of the K18 treatment into your hand and work through your hair evenly from root to tip. If you have short, fine hair, this may well be more than enough, but longer, thicker hair will need more. Work one pump at a time to avoid overloading your hair, and make sure you’re applying evenly. Let the treatment sit for four minutes then continue directly to your styling products - do not rinse.