This article is from the Alternative Medicine Therapies guide.
It is believed that magnets must be placed precisely to have an effect (they work best when placed over a body area that has some degree of intact circulation). Therefore it is ideal to do magnet therapy under the guidance of a doctor or bodyworker (such as a massage therapist) experienced in its use. Many people choose to use magnets on their own, however.
If you are trying magnets for arthritis or another type of pain, you may be advised to purchase small magnetic devices that can be secured to the ailing body part with tape, elastic bandages, or Velcro. These magnets typically generate a magnetic field ranging from 250 to 500 gauss--about 10 times stronger than the magnets on your refrigerator. (A gauss is a unit of measurement for the intensity of magnetic flux.)SOme people believe that magnets may work in part for conditions such as arthritis because taping them to the affected joint acts like a splint, limiting movement.
Depending on how much pain you are experiencing, you might be advised to keep the magnets in place for as little as five minutes or to wear them for a number of hours every day over several weeks. If you are trying magnets for insomnia, your doctor may suggest a magnetic pillow or mattress pad, which may generate as much as 4,000 gauss. (The gauss measurement should be greater when the magnetic source is farther from the body.)
To date, there has not been enough research completed to determine what, if any, gauss level is high enough to be harmful. Because magnetic resonance imaging (MRI) machines generate magnetic fields as high as 15,000 gauss with no known harmful side effects, magnet therapy advocates claim that the strength of therapeutic magnets poses no health risk.