PRP hair restoration typically achieves good results when treatment begins in the early stages of hair loss. The process is more likely to produce desirable results when there are detectable hair follicles. Detectable hair follicles are usually located in areas where the hair is noticeably thinner or more sparse than surrounding areas of the scalp. An exception is the treatment of alopecia areata. Adults with this skin condition may respond well to PRP injections if the affected area or areas are small.