Magnets have been used in alternative medicine for conditions ranging from systemic illnesses to joint pain. Some have proposed using magnets to help heal bone fractures. The idea is that magnets might improve circulation and increase blood flow, and thus the delivery of nutrients, to the fractured bone.
The use of static magnets is probably neither helpful nor harmful in the healing of broken bones. There is no reason to spend money on a static magnet to help a bone heal faster, as it is not likely to provide any benefit.
There is ongoing research into using pulsed electromagnetic fields (PEMF) as a method of electrical stimulation in bone healing. This method is very different from using static magnets. It may be helpful in some healing situations, but research is not definitive and it is just one of the methods of bone stimulation that are used.
Static Magnets and Bone Healing
Static magnets have been a popular alternative healing remedy for many years. But they received a big boost from marketing, especially multi-level marketing, since the 1990s. Magnets are worn close to the body, often incorporated into a wrap, jewelry, mattress pads, and shoe insoles. There is no consensus on how to use a magnet to heal a broken bone. Advocates will recommend wearing the magnet as close as possible to the site of the fractured bone.
Companies and individuals who sell these magnet products tout their benefits for many different purposes, especially to relieve different sources of pain. Research has not shown that these static magnets are useful for treating any condition.
Magnet Safety and Side Effects
If you are considering buying or using a product with static magnets to use while healing from a bone fracture, discuss it with your doctor. It may not be safe to use if you have a pacemaker or insulin pump or other medical devices. You shouldn't use it rather than seeking medical care for a broken bone. If you have symptoms of worsening problems as a broken bone is healing, you should see your doctor.
Within those precautions, using static magnets probably won't cause your problems to get worse. They simply are unlikely to have any benefit.
Pulsed Electromagnetic Field Therapy for Bone Healing
Devices that produce pulsed electromagnetic fields have been used by veterinarians in healing racehorses with broken legs. The medical use of such devices to heal nonunion fractures in humans is being studied. This medical use requires a prescription. There isn't yet conclusive evidence that works for specific types of nonunion and delayed bone healing. Several studies have concluded that it does not speed healing.
Consumer wellness PEMF devices are available. They are not allowed to make medical claims for being effective in treating any disease. Given that the use of PEMF by medical professionals has not yet shown effectiveness, use of these consumer devices for that purpose is unlikely to have any benefit.