Today's research has shown that men and women who have higher levels of dihydrotestosterone (DHT) (both men and women) usually have a higher level of testosterone. Higher levels of DHT is one of the primary causes of thinning hair. Levels of DHT can be brought on by the effects of UV light (sunlight) on the scalp. A phototoxic chemical reaction in the skin caused by exposure to sunlight can form free radicals. Free radicals have a deadly effect on all cells, including the cells that build and regenerate new hair growth in the follicle itself. NX3 can be used by anyone experiencing extreme hair loss or receding hair lines. NX3 is an intensive nutrient treatment containing a special complex of unique time-release ingredients specifically formulated to target all areas of extreme thinning. NX3's free radical scavengers protect hair and scalp from phototoxic effects of sunlight, and the advanced nutrients in NX3 boost the effectiveness of the Bionutrient Treatment. NIOXIN NX3 is not a drug and requires no prescription. This product has NO adverse side effects. Directions for use:Use after NIOXIN #1 or #1C Bionutrient Cleanser and before the Bionutrient Treatment. Rinse completely. Gently blot hair dry. Apply NX3 generously around receding hair lines and all other thinning areas of the scalp with fingertips. Note: satisfactory results cannot be achieved when using a shampoo other than NIOXIN #1 or #1C Bionutrient Cleanser.