Experts have debunked claims that copper bracelets and magnetic wristbands can relieve the crippling pain of arthritis.
Pain sufferers have long believed in the healing powers of the devices with some wearers thinking the bands will help ward off the degenerative disease in their advancing years.
But now scientific research suggests that they have no health benefits.
The research is published in the latest issue of the journal Complementary Therapies in Medicine.
The trial was led by Stewart Richmond, a Research Fellow in the Department of Health Sciences at the University of York, who said: "This is the first randomised controlled trial to indicate that copper bracelets are ineffective for relieving arthritis pain."
"It appears that any perceived benefit obtained from wearing a magnetic or copper bracelet can be attributed to psychological placebo effects. People tend to buy them when they are in a lot of pain, then when the pain eases off over time they attribute this to the device. However, our findings suggest that such devices have no real advantage over placebo wrist straps that are not magnetic and do not contain copper.
"Although their use is generally harmless, people with osteoarthritis should be especially cautious about spending large sums of money on magnet therapy. Magnets removed from disused speakers are much cheaper, but you would first have to believe that they could work."
The trial involved 45 people aged 50 or over, who were all diagnosed as suffering from osteoarthritis. Each participant wore four devices in a random order over a 16-week period - two wrist straps with differing levels of magnetism, a demagnetised wrist strap and a copper bracelet.
The study revealed no meaningful difference between the devices in terms of their effects on pain, stiffness and physical function.