PRP used for hair loss
There are a number of studies and protocols, on how to use PRP for hair loss. In one study, PRP was carried out every two weeks, for a total of 4 treatments and the hair growth was measured after 3 months. In this particular study, the growth was 31% (22 hairs/cm2) after 3 months.
Check My Hair Clinic, for more information on how PRP is used for hair loss.