KEY TAKEAWAY: CGMs can go through airport security in the UK — but which device you're wearing makes a real difference to how you approach the checkpoint.
Walk-through metal detectors are safe for virtually all sensors. Full-body scanners and X-ray machines are where the guidance gets more nuanced, and manufacturers don't all agree on what's acceptable.
Whatever CGM you wear: always inform the security officer that you're wearing a medical device before you approach any scanner, and know that you're always entitled to request an alternative screening method.
Airports like Heathrow, Gatwick, and Manchester process tens of millions of passengers every year — and a growing number of them are travelling with continuous glucose monitors.
Yet despite how common CGMs have become, the guidance around airport security remains surprisingly patchy, inconsistently communicated, and different depending on which sensor you're wearing.
I've worn a CGM through international airport security a number of times, and what I've learned — partly from direct experience, and partly from digging into the official documentation from manufacturers and the NHS — is that this is genuinely worth researching before you travel. Not because security is typically difficult, but because arriving at the checkpoint knowing exactly what applies to your device makes the whole experience considerably smoother.
👉 Also travelling with an insulin pump? Security becomes more layered when you're managing both devices at once. Our guide on Insulin Pumps at UK Airport Security covers every major pump brand and what each manufacturer recommends — including the Omnipod DASH, Omnipod 5, Medtronic MiniMed, and Tandem.
How Does Airport Security Work for CGMs and Medical Devices in the UK?
In the UK, airport security screening is carried out by private security contractors operating under standards set by the Department for Transport (DfT). The process is broadly similar to what you'll encounter elsewhere in Europe and in the World, but there are a few things worth knowing specifically for UK airports.
Unlike the United States, where the TSA publishes relatively detailed public guidance on medical devices, UK airport security guidance for passengers is more general. The practical implication: the conversation at the checkpoint matters more, and being prepared to explain your device clearly is more important than assuming the officer will already know the protocol.
Diabetes UK and the NHS both recommend carrying a letter from your GP or diabetes care team when travelling with diabetes technology like insulin pumps or CGMs — not because it's legally required for UK domestic flights, but because it makes conversations at security considerably easier, and it becomes more important for international travel.
The general framework for all CGMs at UK airports:
- Walk-through metal detectors — safe for virtually all CGM sensors
- Hand-held wanding — safe for virtually all CGM sensors
- Full-body scanners (millimeter wave) — varies by device; check your manufacturer's guidance before you travel
- X-ray baggage belts — most manufacturers advise against putting sensors or receivers through these
And across all of the above: you are always entitled to request an alternative screening method. At UK airports, this typically means hand-wanding or a full physical search. You do not need to justify this request beyond stating that you are wearing a medical device.
Dexcom G7 — The Clearest Guidance at the Airport Checkpoint
The Dexcom G7 is currently the CGM with the most straightforward airport security guidance of any major device on the UK market — and it's a notable improvement on the G6.
According to Dexcom's official documentation, G7 wearers can pass through both walk-through metal detectors and Advanced Imaging Technology (AIT) full-body scanners without removing the sensor. Hand-wanding and a full physical search are also always available as alternatives. Extra sensors travelling in your carry-on luggage can go through the X-ray baggage belt without any effect on performance.
For G7 users, this means genuine flexibility at the checkpoint — you can walk through the full-body scanner without concern, or request an alternative if you'd prefer.
Dexcom provides a downloadable Notice of Medical Device letter for patients, which is worth having on your phone before you travel.
Summary for Dexcom G7:
- ✅ Metal detectors — safe
- ✅ Full-body AIT scanners — safe
- ✅ Carry-on X-ray — safe
- ✅ Hand-wanding and physical search — always available
⚠️G6 users: The guidance above applies to the G7 only. Dexcom advises G6 wearers to avoid AIT body scanners and request a physical search or metal detector instead. If you've recently upgraded from G6 to G7, your approach at security changes — and it changes in your favour.
FreeStyle Libre 2, Libre 2 Plus, and Libre 3 — Know Your Scanner Type
The FreeStyle Libre range is one of the most widely used CGM systems in the UK, partly because it has historically been available on the NHS — making Abbott's security guidance particularly relevant for a large number of British diabetic travellers.
According to Abbott's official documentation, FreeStyle Libre sensors can safely pass through standard walk-through metal detectors.
The concern arises with certain full-body scanners — specifically those using millimeter radio-wave technology. Abbott advises that the extent of exposure from these scanners has not been fully evaluated, and that exposure may damage the sensor or cause inaccurate readings.
The challenge in practice is that it isn't always obvious which type of scanner you're facing at a UK airport checkpoint. The sensible approach is to inform the security officer you're wearing a medical sensor as soon as you reach them, ask what type of scanning equipment is in use, and request hand-wanding or a physical search if there's any uncertainty. Most UK airport security staff are accustomed to this kind of request.
For NHS patients using FreeStyle Libre, Diabetes UK's travel guidance recommends carrying a diabetes travel letter confirming your diagnosis and the devices you're using — particularly useful when travelling through larger hubs like Heathrow or Gatwick where checkpoint queues move quickly and clear communication matters.
Summary for FreeStyle Libre 2 and 3:
- ✅ Metal detectors — safe
- ⚠️ Full-body scanners — safe through some types, not all; ask before proceeding
- ❌ Millimeter radio-wave full-body scanners — do not proceed through; request alternative screening
- ✅ Hand-wanding and physical search — always safe alternatives
Medtronic Guardian Sensor (with MiniMed 670G or 780G)
For those using the Guardian sensor as part of a Medtronic pump system, Medtronic treats the sensor and pump as a single unit — and the security guidance applies to both together.
According to Medtronic's official documentation, the Guardian sensor and transmitter can safely pass through a standard walk-through metal detector. However, both the pump and the Guardian sensor and transmitter must be removed before passing through a full-body scanner — which, since removing a Guardian sensor mid-trip ends the wear session, makes requesting a physical search the only practical option.
Medtronic provides an Airport Information Card for MiniMed users, available through your device documentation or via Medtronic's UK patient support. Having this on your phone before you travel gives you something clear to show if a security officer is unfamiliar with the device.
Summary for Medtronic Guardian:
- ✅ Metal detectors — safe
- ❌ Full-body scanners — do not proceed through; request physical search
- ❌ X-ray baggage belt — avoid
- ✅ Hand-wanding and physical search — recommended approach
👉 CGMs are just one part of travelling with diabetes. From insulin and needles to glucose metres and hypo kits, there's quite a bit more to navigate at UK airport security. Our complete guide on Airport Security Rules for Diabetic Travellers in the UK covers everything — so there are no surprises on the day.
Travelling with insulin? Keep it at the right temperature from departure to arrival with 4AllFamily's insulin travel coolers — designed to meet UK and international airline requirements.
A Note for Those Wearing Both a Pump and a CGM
If you're managing both an insulin pump and a CGM sensor simultaneously — which is increasingly common, particularly among those on closed-loop or hybrid closed-loop systems — you're working with two sets of manufacturer guidelines every time you go through security.
The practical approach, consistent with what both Medtronic and Dexcom recommend: treat both devices as a single system, and apply whichever rule is more conservative. If your pump can't go through the full-body scanner, request a physical search regardless of what your CGM manufacturer says. Inform the security officer about both devices before screening begins, and ask for a single search that covers everything at once.
For those on the NHS-funded hybrid closed-loop programme — which has been expanding across England, Scotland, Wales, and Northern Ireland — this is increasingly relevant, as more people are now wearing pump and sensor combinations as standard care.
What to Say at the Airport Security Checkpoint
The conversation at UK airport security is almost always shorter than you'd expect. Most officers are familiar with medical devices and respond straightforwardly once you've flagged it.
Here's a simple approach that works:
"Hi — I'm wearing a continuous glucose monitor and an insulin pump. They're medical devices that can't go through the body scanner. Could I have a hand search instead, please?"
That's typically all it takes. If the officer is less familiar with CGMs, having your manufacturer's letter or a note from your GP on your phone resolves things quickly.
A few tips that make the experience smoother, based on manufacturer guidance and advice from Diabetes UK:
- Say something before you reach the scanner. Flag it to the officer directing passengers to screening lanes — not when you're already standing at the machine.
- Carry a GP or diabetes team letter. The NHS and Diabetes UK both recommend this, especially for international travel. It doesn't need to be elaborate — a brief letter confirming your diagnosis, your devices, and any medications you're carrying is sufficient.
- Keep spare sensors in your hand luggage. Whatever the X-ray rules say for your model, don't put spares in checked baggage. Airlines lose and delay bags, and a replacement sensor in the hold is no use if your current one fails over the Atlantic.
- Download your manufacturer's documentation before you fly. Dexcom's Notice of Medical Device and Medtronic's Airport Information Card are both available digitally. Having either on your phone takes seconds and can smooth over any uncertainty at the checkpoint immediately.
- Request a hand search if in doubt. It's always available, it's your right, and no justification is needed beyond stating you are wearing a medical device.
👉 Hot destinations, long-haul flights, and hotel rooms with unreliable mini-fridges — keeping insulin at the right temperature when travelling takes more planning than most people expect. My guide on How to Keep Insulin Cool When Travelling covers everything worth knowing, so your medication arrives in the same condition it left in.
FAQs — CGMs at UK Airport Security
Can I wear my CGM through airport security in the UK?
Yes. CGM sensors can be worn through walk-through metal detectors at UK airports without any issue. Full-body scanners are where the rules differ by device — the Dexcom G7 is cleared for AIT body scanners, while FreeStyle Libre 2/3 and Medtronic Guardian users should avoid certain scanner types. If you're unsure, request a hand search — it's always available.
Do I need a letter from my GP to fly with a CGM?
It's not a legal requirement for UK domestic flights, but both the NHS and Diabetes UK recommend carrying one — particularly for international travel or if you're also carrying insulin, needles, or other diabetes supplies. A brief letter from your GP or diabetes care team covering your diagnosis and devices is usually sufficient.
Will I be asked to remove my CGM sensor at security?
No — and you shouldn't be. CGM sensors are applied under the skin and cannot be removed without ending the wear session. If a security officer asks you to remove it, calmly explain this and ask for a hand search instead. If the situation isn't resolved, request a supervisor.
Can CGMs go through X-ray baggage machines?
Most manufacturers advise against it for sensors, transmitters, and receivers. The Dexcom G7 is the exception — spare sensors and the receiver can safely go through carry-on X-ray. For FreeStyle Libre and Medtronic Guardian, ask for a visual inspection of your supplies rather than sending them through the belt.
What about travelling to EU countries after Brexit?
For travel from the UK to EU destinations, it's worth carrying a translated version of your medical device letter or GP note if possible, and checking the entry requirements for any medications you're carrying.
Is FreeStyle Libre available on the NHS?
Yes — FreeStyle Libre 2 and Libre 3 are available on NHS prescription for eligible patients with Type 1 diabetes and some patients with Type 2 diabetes. If you receive your sensor through the NHS, the same airport security guidance applies regardless of how your device is funded.
💬 We'd Love To Hear From YOU!
Have you travelled through a UK airport with a CGM?
Whether your experience at security was smooth or unexpectedly complicated, share it in the comments — the more we share as a community, the better prepared every diabetic traveller can be.
