Wash the hair with the Agi One deep cleansing shampoo. (wash the hair twice). Leave on the first deep cleanse shampoo for 2-5 minutes to remove excess oils and build up. The first shampoo does not generally lather up a lot however upon applying the 2nd shampoo you will find it lathers up, if it does not then re shampoo a 3rd time. This will be very rare.