Like most runners faced with a nagging injury, Camelia Marculescu—a competitive runner on the Charleston, South Carolina, race scene—tried to shrug off the persistent stiffness and aching in her right Achilles tendon. But the more she ran, the worse it got, until she was limping constantly and even her easy runs felt hard. Even worse, Marculescu, 43, began to develop the same symptoms in her left leg. The usual physical therapy treatments—ice, ultrasound, stretching—didn’t help much. After a few months, Marculescu, an infectious disease physician, felt more drastic measures were needed. After an MRI revealed a partial tear in both Achilles tendons, she signed up for surgery to repair the more severely injured right leg. But rather than undergo the knife on the left leg, as well, she asked her doctor for a platelet-rich plasma (PRP) injection. “Being a physician myself I had researched PRP from all angles—studies, anecdotal evidence, proposed mechanism of action. I wanted to avoid surgery on that left leg at any cost and was desperate for relief.”

PRP isn’t anything brand-new; it’s been used in sports medicine centers around the country for at least a couple of years and its purported success has been popularized by marquee athletes like Tiger Woods and Pittsburgh Steeler Hines Ward. The treatment is straightforward enough: Your blood is drawn, then spun in a centrifuge that extracts the platelets. These platelets themselves are then injected into the injury site. The theory: Platelets secrete a growth factor and provide nutrients that stimulate tissue recovery.

The treatment appears to work best for injuries like tendonitis (inflammation of the tendon) or tendonopathy (a tear in the tendon), but some sports medicine experts say it’s far from a cure-all. “You won’t see too many orthopedists using PRP as a first-line treatment,” notes David Geier, director of sports medicine at the Medical University of South Carolina. “Most of the time injuries like these get better on their own or with more conservative treatments like physical therapy.”

PRP is expensive (anywhere from $500 to $1,200 per shot, depending on where you live and what your doctor charges) and is rarely covered by insurance. More important, there’s not a lot of good research that shows PRP is better than a placebo. “When there’s no control group in the study you’ll often see some improvement, but there’s really no strong supportive evidence the treatment works,” adds Matthew Matava, an associate professor of orthopedic surgery at Washington University Medical Center in St. Louis.

That hasn’t stopped Geier or Matava from giving the treatment to their patients because, as Geier notes, “The vast majority of people do get better eventually, but the ones that don’t are miserable and we want to do everything we can to help them. It’s still a good option for those who are looking for an answer.” Most patients report minimal side effects aside from some slight pain around the injection site.

In Marculescu’s case, at least, her experience was entirely positive. Six weeks after receiving her second PRP shot and about three months after her surgery, both legs felt better — enough for her to lace up her shoes and get out for a run. “I saw a significant improvement in pain and discomfort after about three weeks and now, eight months after treatment, I’d say it’s at least as effective as the leg that had the surgery.” Today she’s eyeing a 10K race in October and a half-marathon early next year. “I’m not saying this procedure is for everyone, and it certainly doesn’t cure very single case, but for people like me, it’s worth a shot.”

—Alyssa Shaffer, Women’s Health Reporter