Someone's finally gone and done the studies to see if what we all knew - that copper and/or magnetic bracelets have no actual effect on arthritis - is actually true, or if there might have been something in the woo.
Nope, they're pure placebo.
I do wonder where the whole myth came from in the first place. Not why it persists, because there is an entrenched industry very interested in maintaining sales. But who first persuaded someone that it worked?