My GP recommended this product. There is a display box for it on the store shelf, which you need to take to the counter at the prescription area, in order to acquire the product itself. I was recommended to use it twice weekly for four weeks. This is only the second time I’ve used it and my itchy scalp is no more, as well as dandruff banished. Not much product is required at all, it is very potent and consistency is fairly runny and pink in colour, so I use a ten cent piece worth and I have mid-length to long hair. Given its price, this is a good thing! You need to leave it in contact with your scalp 3-5 minutes for effectiveness. If you also have dry hair, you may want to consider a conditioner, after using it, at least, a leave-in conditioner for the ends, as this shampoo leaves vour hair “squeaky clean” (I have oily hair). It has a very strong scent as well. depending on your taste this may or may not appeal. I am very pleased so far.