TORONTO - Ultimate fighting champion Georges St-Pierre got it to repair a groin injury. Pittsburgh Steelers Hines Ward and Troy Polamalu used it to heal damaged knees before the Super Bowl. And it may have allowed Los Angeles Dodger Takashi Saito's elbow to mend so he could pitch in the fall pennant race.

It is platelet-rich plasma therapy, or PRP, a treatment that has become a mainstay of sports medicine practitioners, both for healing professional athletes and recreational amateurs.

PRP is also one of the treatments provided by Toronto sports doctor Tony Galea, who has been charged with administering and selling an unapproved drug, a calf's blood extract called Actovegin.

But there is nothing illegal about platelet-rich plasma therapy, said Dr. Ian Cohen, a sports medicine specialist at the University of Toronto.

"There's no issue with respect to doping. It's absolutely not a form of doping," Cohen said Wednesday. "It's taking a concentrated version of the patient's own healing nutrients and applying it to their injured area."

The treatment, used for such chronic conditions as tennis elbow and rotator cuff injury, uses the patient's own blood to help assist healing.

A small amount of blood is drawn from the patient, which is then spun in a centrifuge machine to separate platelets and plasma from the red and white blood cells. The serum containing the platelets is then injected at the site of the injury.

The platelets break down and incite an inflammatory reaction, which prompts the release of substances that promote tissue repair, said Cohen.

"So the platelets help to trigger the reaction that you're looking for. The platelets act as a catalyst for a healing response."

Studies have shown that an injection of platelets encourages injury repair better than a placebo (usually a saline injection), he said. "I've certainly referred patients for treatment and seen some success."

Each treatment can run from about $300 to more than $700, most of which is not covered by provincial health insurance. Depending on the injury and the individual patient's response, a few treatments may be needed over several months.

"Athletes are ideal patients because they're very highly motivated to get back to their activity, so they're often looking for innovation and treatments that allow a faster return to function," Cohen said.

But professional and elite amateur athletes aren't the only ones being given the therapy.

"We use it on athletes of any calibre. Weekend warriors would be candidates and I suspect that this technique will become more common in work-related injuries as well, also overuse injuries," he said.

"It's not based on how the injury happened; it's based on the diagnosis. So it could have happened from work, it could have happened in a motor vehicle accident, it could have happened from sports. It's the effect that you're looking for, not the cause of the injury."

Dr. Gordon Ko, a rehabilitation physician at Sunnybrook Health Sciences Centre in Toronto, uses platelet-rich plasma therapy to treat patients with ligament damage that causes chronic low back pain, as well as for other tendon or ligament injuries.

"I use it primarily in treating patients with chronic pain," said Ko, who also has a clinic in Markham, Ont., just north of Toronto.

"Those types of patients respond remarkably well when we inject the ligaments with the platelets," he said, explaining that blood-clotting platelets secrete growth factors, which attract collagen-producing cells that encourage ligament repair.

"We've done hundreds of these types of injections over the years."

But Ko said PRP has other applications beyond sports injuries, including their use in burn patients and those undergoing gum-related dental surgery.

"We have many other specialists using platelets."