Are Magnets Safe Near Pacemakers and Medical Implants?
Keep magnets away from pacemakers, implantable defibrillators (ICDs) and other implanted devices. Fields of 10 gauss (1 millitesla) or more can switch many of these devices into “magnet mode,” which changes how they work while the magnet is near. The FDA advises keeping phones and smart watches that contain magnets at least 6 inches (15 cm) from an implant. Large neodymium magnets reach farther, so we recommend 12 inches (30 cm) for magnets 1 Inch and larger. Always follow your doctor’s and your device maker’s guidance.
This Is General Safety Information, Not Medical Advice
If you have an implanted device, ask your cardiologist or the device manufacturer what distance is right for you. Devices and settings differ.
What “Magnet Mode” Does
Pacemakers and ICDs include a magnetic sensor so doctors can change how the device behaves during surgery or testing by placing a magnet over it. A strong consumer magnet can trigger the same response. For many pacemakers that means pacing at a fixed rate; for many ICDs it means shock therapy is paused while the magnet is present. Most devices return to normal once the magnet is removed, but behavior varies by model, which is why distance matters.
How Far Our Magnets Reach
We calculated where each size’s field falls below 10 gauss, measured straight out from the pole face (the strongest direction):
Practical Precautions
- Keep magnets 6 in (15 cm) or more from the implant, and 12 in (30 cm) for magnets 1 Inch or larger, stacks and pot magnets.
- Never carry magnets in a shirt or jacket pocket over the device, and don’t rest them on your chest.
- Choose clip or lanyard badges instead of magnetic name badges.
- Let someone else handle large magnets, especially separating or stacking them, since that brings them close to your body.
- Watch for the same issue with other devices. Programmable shunt valves, neurostimulators, cochlear implants and insulin pumps can also be affected by strong magnets. Check the device’s instructions.
Sources
- Magnets in Cell Phones and Smart Watches May Affect Pacemakers and Other Implanted Medical Devices (U.S. FDA, 2021)
- Impact of magnetic fields from tablets, laptops, smartphones, and household/leisure magnets on cardiac implantable electronic devices (Journal of Arrhythmia, 2025), source of the 10 gauss activation level
- Distances calculated by totalElement for N52 discs from magnet dimensions and material properties.