What the researchers wanted to know: Do the commercially available magnetic bracelets help relieve pain from arthritis of the hip and knee?

What they did: Over the space of two years, researchers found 194 people between the ages of 45 and 80 who suffered from medically documented osteoarthritis of the knee and hip. (They excluded people who already used magnetic jewelry in an attempt to beat their pain.)

Scientists divided the people into three groups: Some got a bracelet with magnets set in a way to cause a standard-strength magnetic field across the wrist, some got bracelets with very weak magnets, and another group got bracelets with nonmagnetic steel washers. Participants didn't know what kind of bracelet they were getting. Using a standardized pain scoring system, they rated their symptoms both before and after wearing the bracelets. Patients continued their usual pain management treatment during the experiment, so any effects from the magnets would be additional.

What they found: The strong magnets helped. The average pain scores were 1.3 points lower in the group with the standard magnetic bracelets than the dummy bracelets. Results for the weakly magnetic bracelets were about the same as the dummy ones.
Harlow, T. et al. "Randomised Controlled Trial of Magnetic Bracelets for Relieving Pain in Osteoarthritis of the Hip and Knee." British Medical Journal. Dec. 18–25, 2004, Vol. 329, pp. 1450–1454.