With claims that it can cure everything from impacted molars to Achilles tendonitis to hair loss, platelet-rich plasma has become the hottest new treatment option in the medical field. But are these claims legit, or is this just another passing fad?

For starters, let's talk about what platelet-rich plasma therapy is — and what it's not. Platelets are small blood cells that are critical in the healing process. When a wound or injury occurs, platelets rush to the area and form clumps, or clots, that stop the bleeding. They also release hormones that help initiate tissue recovery.

The theory behind platelet-rich plasma therapy, or PRP, is that increasing the number of platelets to an area will promote wound healing and speed up recovery times. For the treatment, a small vial of a patient's blood is taken and spun in a centrifuge to separate the platelets.This concentrated, or platelet-rich, plasma is then injected into the patient at the site of the injury. The additional platelets will then promote healing in the damaged area.

If it works, PRP could change the way wounds and injuries are treated, speeding healing time, preventing scarring and reducing the risk of infection. It could be used across medical fields from plastic surgery to orthopedic treatment to cardiac procedures to help patients heal and recover from injuries.

But that's a big if. Unfortunately, there is little evidence to date that PRP works.

Although a number of studies have found PRP effective in treating various ailments, even doctors who offer PRP as a treatment option of their patients agree that more and better studies are needed before any real claims can be made about the effectiveness of the procedure. For example, in this study in The Journal of Cutaneous and Aesthetic Surgery, 11 patients with androgenic alopecia (male-pattern baldness) were treated with PRP and evaluated over a period of 12 weeks. While the study's authors conclude PRP is an effective treatment for androgenic alopecia, they acknowledge that their sample size is very small, no control option was offered and the follow-up period was minimal.

According to a recent article in Scientific American, PRP has been used since the mid-1990s to promote healing after spinal injuries and plastic surgery. High-profile athletes such as golfer Tiger Woods, Los Angeles Dodgers' pitcher Takashi Saito and two Pittsburgh Steelers (Hines Ward and Troy Polamalu) have used PRP to treat sports-related injuries, and since then, the treatment has skyrocketed in popularity, particularly among patients who haven't found relief from other treatment options.

Dennis A. Cardone, an osteopathic doctor at the New York University Hospital for Joint Diseases, is currently using PRP for amateur athletes with a variety of sports-related injuries. In an interview with Scientific American, Cardone said the anecdotal evidence from patients who claim to feel relief from PRP is enough to make the treatment option available to patients who have not had success with traditional medical treatments. Still, he's eager to see studies that show whether PRP is effective or if it is just the good old placebo effect at work.

"The bottom line is that we don't know enough about PRP therapy," said Cardone. "It is safe. We're using it. Anecdotally it certainly seems to have some positive effects. How much we'll be using it in the future or what we'll be using it for, those are all questions that really remain to be answered."