A wearable magnetic device, a method for subjecting a body region to a magnetic field and a set of parts. The wearable magnetic device comprises a magnetic structure configured to generate a magnetic field in a field area of the device; an auxiliary magnet connected to the magnetic structure and configured to increase the intensity of the magnetic field in the field area of the device; and a fastener; wherein the auxiliary magnet and the fastener are configured to magnetically secure the fastener on a side of the auxiliary magnet facing away from the field area of the device with a piece of fabric or a piece of garment disposed between the auxiliary magnet and the fastener.