Inthe blood

It’s been about a decade since newspapers started reporting on the first elite athletes undergoing injections of their own blood to heal their injuries.

Golf giant Tiger Woods received shots of his own blood platelets after knee surgery, before he went on to play in four professional majors in 2009. Two Pittsburgh Steelers got shots of their blood plasma before winning the Super Bowl. A major league pitcher received an injection of his blood platelets into his elbow. A dozen or so professional soccer players were getting plasma injections, as was Olympic sprinter Donovan Bailey.

Fast-forward 10 years, and platelet-rich plasma injection—or PRP therapy—is no longer the exclusive medicine of super-athletes. It’s almost mainstream, with more than 500 clinics in the United States alone offering the therapy.

Almost mainstream, but not mainstream—yet—because most insurance companies, including public health agencies, refuse to cover the procedure, claiming evidence for PRP’s effectiveness is inconclusive. What does the science say?

Does it work?

If you search for “platelet-rich plasma” on the US National Library of Medicine website (pubmed.gov), roughly 10,000 references pop up. Just in 2019 alone, studies have reported its use experimentally to treat gunshot wounds,¹ diabetic ulcers,² Bell’s palsy,³ male pattern hair loss,⁴ infertility⁵ and even in dentistry.⁶

Most of the studies, however, provide evidence for the therapy’s usefulness in accelerating healing after orthopedic surgery and treating soft tissue injuries: tears of ligaments, tendons and meniscus (a strip of fibrocartilage on the knee), tendinitis, rotator cuff injuries, tennis elbow, frozen shoulder and arthritis—especially knee arthritis.

“There’s actually a lot of scientific evidence to support PRP now,”says