It is used to treat psoriasis of the scalp. It should be applied thinly directly onto a dry scalp once daily, taking care to massage the shampoo into the affected areas of the skin on the scalp. The shampoo should be left on for 15 minutes; the scalp must NOT be covered (eg with a shower cap) during this time. After 15 minutes the shampoo can be rinsed off with water, or the hair can be washed using your regular shampoo. Hair can then be dried as usual.