Flying With Insulin: TSA Rules and How to Keep It Cold

I've lived with diabetes for 10 years. On a cruise to the Bahamas, I tucked my insulin pen under a beach towel to keep it out of the sun. Hours later my blood sugar was over 400 and my insulin was ruined. That trip is the reason InsulCool exists, and it's why I take travel day seriously.

This guide covers how to travel with insulin from your front door to your hotel room: what TSA allows, what to do at the checkpoint, and how to keep insulin cold while traveling.

TSA insulin rules: what you can bring

TSA treats insulin and diabetes supplies as medically necessary items. That means:

• Insulin in any form: vials, pens, cartridges and pre-filled syringes. TSA asks that insulin in any form or dispenser be clearly identified, so keep the pharmacy label or original box.
• Liquids over 3.4 oz: medically necessary liquids are allowed in reasonable quantities for your trip. You just have to declare them for inspection.
• Insulin pumps, CGMs and pump supplies: pump supplies must be accompanied by insulin.
• Ice packs and gel packs: allowed when they're keeping medication cool, whether they're frozen, partially frozen or melted.
• Juice or glucose gels for treating lows.

The final decision always rests with the officer at the checkpoint, so make it easy for them: keep everything together, labelled, and ready to show.

Ice packs vs. bio gel packs: they're not the same thing

A regular ice pack is frozen water, or a gel that freezes even colder. Straight out of the freezer it's well below 32°F, the temperature where insulin freezes, and a pen sitting against it can freeze too. Frozen insulin is ruined, even after it thaws. Bio gel packs and bottles made for medication coolers are designed to change state at around 36°F, just above insulin's freezing point, so they keep medication cold without freezing it.

Can you bring insulin needles on a plane?

Yes. You can bring unused syringes and pen needles on board as long as they're with the insulin or injectable medication they're for. Pack them in the same pouch as your insulin so they're screened together.

Bring a small travel sharps container for used needles. Don't loose-pack them in your bag.

Getting through the security checkpoint

1. Tell the officer first. Before screening begins, say you have diabetes and are carrying medical supplies. You can also hand over a TSA notification card if you'd rather not say it out loud.
2. Take your supplies out. Place your insulin, needles and cooling case in a separate bin, just like a laptop.
3. Mention any device you're wearing. If you have a pump or CGM on your body, tell the officer where it is before you walk through.
4. Ask for a hand inspection if you prefer. Under normal conditions, insulin can safely go through the X-ray machine. If you're not comfortable with that, you can ask for your insulin to be inspected by hand instead. For pumps and CGMs, follow your device manufacturer's instructions.

Need extra help? TSA Cares can arrange assistance for travellers with medical conditions if you contact them before your flight.

Do you need a doctor's note? TSA doesn't require one. But a doctor's letter and pharmacy-labelled packaging can speed things up if you're pulled aside for additional screening. They're also worth having if you need a refill while you're away.

Why insulin should never go in your checked bag

The cargo hold can get very cold, and bags can sit on a hot tarmac before loading. Insulin that freezes or overheats can lose its strength without looking any different. Checked bags also get delayed or lost. Keep all of your insulin, plus a backup supply, with you in the cabin.

How to keep insulin cold while traveling

This is where most travel guides stop, and where most problems start. A travel day can mean 10 or more hours away from a fridge: the drive to the airport, security lines, a delayed gate, the flight, and a warm rental car at the other end.

Unopened insulin should be stored in the fridge at 36–46°F. Once it's in use, most insulin can stay at room temperature for a limited time, generally below 86°F, but that time varies by type. Check your package insert or ask your pharmacist about yours.

A few things that make a real difference:

• Keep your cooler under the seat in front of you, not in the overhead bin. You can check on it, and overhead bins can get warm during ground delays.
• Keep it out of direct sunlight. That goes for window seats, beach bags and car dashboards.
• Know your power options. Some planes have USB ports at the seat and some don't. A power bank means you're never relying on the airline. Power banks must travel in your carry-on, never your checked bag. TSA and the FAA limit them by watt-hours (Wh), not milliamp-hours (mAh): up to 100Wh, about 27,000mAh, is allowed without airline approval. Some airlines set stricter limits, so check yours before you fly.
• New: the InsulCool power bank, available October 15. Keep the Icelander running through security lines and gate delays. Keep everything together in the InsulCool carrying case.
• Plan the hotel. Ask for a room with a fridge when you book, and check that it isn't set so cold that it freezes things.

Flying with Mounjaro, Ozempic and other GLP-1 pens

The same steps apply to GLP-1 pens. Declare them as medically necessary medication, keep them in your carry-on, and keep them cold. Single-dose Mounjaro and Zepbound pens are wider at the base, so they take more room in a case. The Icelander fits up to 3 when plugged in (one packed upside down) or up to 2 with the gel bottle. Storage limits differ by medication, so check your pen's label before you fly.

International flights and time zones

Other countries have their own security rules, so check the rules for your destination and any connecting airports before you go. Bring double the supplies you think you'll need, split between two bags you carry yourself.

Crossing time zones can affect when you take your doses. That's a conversation for your doctor before you travel, not something to work out at the gate.

Flying with insulin: packing checklist

• Insulin, plus a backup supply, in its labelled packaging
• Unused pen needles or syringes
• Insulin cooler, charged or with a frozen gel bottle
• Power bank, 100Wh or less (carry-on only)
• Glucose meter, CGM supplies and spare pump supplies
• Fast-acting glucose for lows
• Travel sharps container
• Doctor's letter and copies of prescriptions
• TSA notification card (optional)