Because PRP is obtained from your own blood, there are no foreign compounds or chemicals injected into your scalp. The injections themselves are done with a very fine needle and there is generally some mild pain during the injection procedure. Afterwards, there can be bruising, a mild sensation of soreness, headache, slight swelling, or tingling. Because the needle is so fine, there are no wounds or open sores that result from the injections and there is no need for any special care of the scalp afterwards. The risks of drawing the blood from a vein in your arm are the same as when blood is drawn for a standard laboratory test. There can be an ache or pain in your arm during the blood draw, and a bruise may form at the site which can last for 1-2 weeks.
You should not receive PRP injections if you currently have cancer, or are pregnant or breast feeding.