iPhone MagSafe and Insulin Pump

Hello. I am considering getting an iPhone 13 but am concerned about the MagSafe feature interfering with my pump (Tandem tslimX2). Does anyone here have an iPhone 12 and a pump?


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I’ve got the iPhone 12 pro and it has occasionally ended up in the same pocket with the pump (same pump as yours) with no discernible adverse effects in my experience.

@MBW Thanks. Do you use a Dexcom too? I’ve just heard that there the potential for the MagSafe to interfere with the Dexcom sensor?

Yes I use Dexcom since almost a year and I have not noticed anything interfering with the signal form the transmitter to my phone or to the tandem pump. The sensor is on my upper arm and the Horne is usually on my desk, or in my pocket, or on the bedside table when I’m asleep. But very rare loss of signal (like every 1-2 months) and usually got 1/2 hour or so.
But I should perhaps clarify that I don’t charge my phone with MagSafe. I just know that it has the capacity to be charged by it. I plug the phone in to a USB charger.

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I don’t have a pump or an iPhone with MagSafe. I do have an Apple Watch 6 which uses very weak magnets in the watch and charger. The charger magnets are more powerful, but not extremely strong.

From what I understand a strong magnetic field can alter the magnets in the pump motor, causing it to either work wrongly or not at all. I am going to post the section from Apple’s user guide on the iPhone 12 with MagSafe. They are not being particularly helpful, suggesting you contact the manufacturer of your device.

Medical device interference iPhone contains magnets as well as components and radios that emit electromagnetic fields. These magnets and electromagnetic fields may interfere with medical devices, such as pacemakers and defibrillators.

Though all iPhone 12 models contain more magnets than prior iPhone models, they’re not expected to pose a greater risk of magnetic interference to medical devices than prior iPhone models.

Consult your physician and medical device manufacturer for information specific to your medical device and whether you need to maintain a safe distance of separation between your medical device and iPhone. There are many types of medical devices, and manufacturers often provide recommendations on the safe use of their devices around wireless or magnetic products to prevent possible interference. If you suspect iPhone is interfering with your medical device, stop using iPhone.

Luis, always a technician until they carry me out.

Thanks, Luis. You’re right, they’re not being very helpful. I actually did ask my endo (I had an appointment with him today) but he didn’t know.

Maybe I’ll try calling tandem and asking them… it’s frustrating because if the MagSafe truly is a problem, i guess that means I’ll have to switch to android….I would assume all iPhones going forward will have this feature.

According to the X2 user manual,

Your pump has been designed to withstand common electromagnetic interference including airport metal detectors.


The System is suitable for use in all establishments, including domestic establishments and those directly connected to the public low-voltage power supply network that supplies buildings used for domestic purposes.

I’m all for team Android, but I would have a real hard time imagining your iPhone emits more electromagnetic force than a metal detector. It’s only especially strong magnetics, like MRIs, and high voltage power equipment that pose a problem.

The specs are in the back of the user manual, around page 335. The guidance is given at ±8,000 volts with direct contact, or ±15,000 volts through the air. MagSafe has a max output of 9 volts, not even remotely in the same ballpark.


I don’t think the concern is the voltage of the MagSafe, but the close proximity of magnets that could affect the magnets in the pump motor. I think it is unlikely, but is something that the design teams at the various pump manufacturers should carefully test and address clearly. It should not be left to anecdotal experience by users who could be harmed.


But it’s all relevant. We’re talking about electromagnets in these systems. The greater the voltage = the greater the magnetic force. They’re directly proportional.

It’s a weak magnet and not a problem.

The Bluetooth signal used to communicate by it’s very nature is very weak. That’s why it’s available for unregulated use. So interference is always going to be a problem. MagSafe doesn’t pose anymore issue to communications than wireless devices, microwaves, any other cell phone, water (including your body) or other physical objects blocking the signal, etc… And it definitely doesn’t pose a physical threat to the pump. That’s why the specifications exist in the back of the manual.

Regardless whether the motors have permanent magnets or using coils on ferrite cores they can be affected by external magnetic fields that do not involve voltages (electromagnetic fields).

The iPhone magnets do not supply voltage and current. That is from the MagSafe charger. But, both the charger mat and the phone do have magnets and thus, magnetic fields.

As I said, probably not strong enough to to affect the pump motor, but without real testing in a lab there’s no way to be sure. It could happen if the iPhone and the pump are in one particular position, but not is others, i.e. the phone magnets positioned very close to the motor fields.

Magnetic fields rapidly decrease with an increase of distance.

Once again, this has nothing to do with voltage. That’s a whole ‘ other issue.