The Food and Drug Administration (FDA) is advising the public that some consumer electronic devices (eg, cell phones, smart watches) with high field strength magnets may cause certain implanted medical devices to switch to “magnet mode” and suspend normal operations.

To allow for safe operation during certain medical procedures, such as undergoing an MRI scan, many implanted medical devices, such as pacemakers and cardiac defibrillators, are designed with a magnetic safe mode. This safety feature is initiated when a high field strength magnet is placed near the implanted device, which may cause the device to stop working or change how it works (ie, a cardiac defibrillator may be unable to detect tachycardia events).

To better understand the effect of consumer electronics with high field strength magnets on medical devices, the FDA reviewed recently published articles and conducted its own testing to confirm and provide appropriate recommendations for patients. “We believe the risk to patients is low and the agency is not aware of any adverse events associated with this issue at this time,” said Dr Jeff Shuren, MD, JD, director of the FDA’s Center for Devices and Radiological Health. “However, the number of consumer electronics with strong magnets is expected to increase over time.”

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In March 2021, Apple issued an update regarding the magnets inside their iPhone 12 models and MagSafe accessories stating that while these newer models contain more magnets, they are “not expected to pose a greater risk of magnetic interference to medical devices than prior iPhone models.” Consumers were advised to consult with their physician and medical device manufacturer for recommendations specific to their implanted medical device.

Based on their findings, the FDA is advising individuals with implanted medical devices to consider keeping consumer electronics at least 6 inches away from the device. Additionally, patients should refrain from carrying consumer electronics in a pocket over the implanted medical device. Health care professionals and patients are also encouraged to report adverse events or safety problems to the FDA’s MedWatch program.


  1. FDA In Brief: FDA continues to monitor the effects of magnets in consumer electronics on implanted medical devices. [press release]. Silver Spring, MD: US Food and Drug Administration; May 13, 2021. 
  2. Magnets in cell phones and smart watches may affect pacemakers and other implanted medical devices. [press release]. Silver Spring, MD: US Food and Drug Administration; May 13, 2021.
  3. About the magnets inside iPhone 12, iPhone 12 mini, iPhone 12 Pro, iPhone 12 Pro Max, and MagSafe accessories. Apple Inc. Accessed May 14, 2021.

This article originally appeared on MPR