PRP injections are used to treat torn tendons, tendinitis, muscle injuries, arthritis-related pain, and joint injuries. They’re becoming more common for cosmetic procedures, too. For example, dermatologists and hair replacement experts use PRP injections to treat a type of hair loss called androgenic alopecia, also known as male or female pattern baldness, which affects men and women. And some dermatologists provide PRP treatments for the face.