Magnet therapy involves the use of a magnetic device placed on or near the body to relieve pain and facilitate healing. The magnetic products on the market today come in many forms. They can be taped to the skin, worn as jewelry or in your shoes, or slept on as pillows and mattresses. Arthritis, insomnia, carpal tunnel syndrome, and headaches are among the long list of ailments for which people have tried magnet therapy. Although no one can say how magnets work, advocates claim that they can have a profound effect on the body, particularly in relieving pain.