Magnet therapy, magnetic therapy, or magnotherapy is an alternative medicine practice involving the use of static magnetic fields. Practitioners claim that subjecting certain parts of the body to magnetostatic fields produced by permanent magnets has beneficial health effects. Magnet therapy is considered pseudoscientific due to both physical and biological implausibility, as well as a lack of any established effect on health or healing. Although hemoglobin, the blood protein that carries oxygen, is weakly diamagnetic and is repulsed by magnetic fields, the magnets used in magnetic therapy are many orders of magnitude too weak to have any measurable effect on blood flow.