Flying with medication
Most medication is permitted in both carry-on and checked baggage. The rules that matter are those governing liquid volumes, controlled substances, and destination-country import restrictions — not whether you can take it through the security checkpoint.
General rule
Medication — prescription or over-the-counter — is permitted in carry-on and checked bags on virtually all commercial airlines. Aviation security authorities in the US, EU, UK, Australia, and most other jurisdictions explicitly exempt medication from the standard prohibited items list. Carrying medication in your carry-on is generally advisable so it stays with you if checked luggage is delayed or lost.
Liquid medication over 100 ml
The standard 100 ml liquids rule has a medical exemption in most jurisdictions. Liquid medication exceeding 100 ml — including eye drops, suspensions, solutions, and nutritional supplements in liquid form — may be carried in your cabin baggage provided you declare it separately at the security checkpoint. It does not need to go in the 1-litre clear bag.
- Remove liquid medication from your bag before the X-ray belt
- Tell the officer it is medication when you present it
- Carry supporting documentation (prescription, pharmacist label)
- Be prepared for additional screening — visual inspection or swabbing
- Original pharmacy label on the container
- Prescription printout or pharmacy receipt
- Doctor's letter for unusual or large quantities
- Supply matched to journey length is less likely to raise questions
Prescription medication
Keep prescription medication in its original pharmacy packaging wherever possible. The label on the container — patient name, medication name, dosage, prescribing pharmacy — is your primary form of identification at both security and customs.
For longer journeys, or when travelling with multiple medications, carry a copy of the original prescription or a letter from your doctor. This is not a legal requirement in most countries for personal-use quantities, but it resolves questions quickly and prevents delays at both security screening and destination customs.
Supply quantities that clearly match the journey length are treated as personal use. Carrying several months' supply of a controlled substance invites scrutiny regardless of documentation.
Controlled substances
Controlled substances — opioids, benzodiazepines, stimulants such as methylphenidate, and other scheduled drugs — require extra care. The rules differ between countries, and a substance that is a legal prescription in your home country may be restricted or prohibited at your destination.
For travel within the Schengen Area carrying controlled substances, a Schengen certificate (also called a narcotic drug certificate) is issued by national health authorities. It identifies the patient, the medication, and the travel itinerary. Some Schengen countries require it for stays exceeding 3 days; others recommend it for any quantity. Check with the relevant national authority before travel.
Several countries prohibit import of substances that are routine prescriptions elsewhere. Japan prohibits stimulants including some ADHD medications. The UAE restricts several opioids and benzodiazepines. Singapore requires prior approval for controlled drugs. Check destination rules well in advance — not at the airport.
See the medication destination rules page for country-specific controlled substance restrictions.
Needles and syringes
Hypodermic needles and syringes are permitted in carry-on baggage when there is supporting documentation of a medical need. This applies to insulin-dependent diabetes patients, individuals carrying epinephrine auto-injectors (EpiPen), and others with a documented injectable medication requirement.
Carry the associated medication alongside the needles. A pharmacist label, prescription, or doctor's letter linking the patient to the medication is sufficient documentation in most jurisdictions. Unused syringes without medication or documentation are more likely to be questioned. Sharps must be capped.
Inhalers
Metered-dose inhalers (MDIs) and dry-powder inhalers are permitted in carry-on bags without restriction. They are not classified as liquids for screening purposes and do not count toward the 1-litre liquids allowance.
In checked baggage, pressurised MDI canisters are subject to aerosol limits. Most airlines cap total aerosol volume in the hold at 2 litres or 2 kg per passenger. Personal-use quantities of inhalers are well within these limits, but confirm with your airline if you are travelling with large quantities of spare inhalers.
Medical cannabis
Cannabis in any form — including products prescribed as medical cannabis — is prohibited on virtually all international flights. This applies regardless of whether cannabis is legal in the country of origin and regardless of whether the destination permits it.
In the United States, this situation is complicated by the conflict between federal and state law. Cannabis remains a Schedule I controlled substance under federal law. Aviation security (TSA) and aviation operations fall under federal jurisdiction. Even on a domestic US flight between two states where cannabis is legal, TSA officers are federally mandated to refer any cannabis discovery to law enforcement. Carrying medical cannabis on a US domestic flight is not protected by state medical marijuana laws.
CBD products derived from hemp with less than 0.3% THC occupy a different legal category in some jurisdictions, but their treatment at security and customs varies widely. Do not rely on origin-country legality when crossing an international border.
Doctor's letter — what it should contain
A doctor's letter is not universally required but resolves ambiguity at both security checkpoints and destination customs, particularly for controlled substances, large quantities of medication, or injectable medications. A useful letter includes:
- Patient full name and date of birth
- Name of each medication (generic and brand name)
- Dosage and form (e.g., 10 mg tablets, 5 ml/day oral solution)
- Medical condition being treated — in general terms if the patient prefers not to disclose the specific diagnosis
- Duration of travel and the quantity of medication being carried
- Whether any medication requires refrigeration or special handling
- Doctor's full name, medical registration number, and specialty
- Practice name, address, and contact telephone number
- Doctor's signature and date
A letter on practice letterhead carries more weight than an informal note. For controlled substances crossing international borders, some countries may require a certified translation.
The above covers what you can carry on the aircraft. Whether you can import medication into your destination country is a separate question governed by destination customs law. See medication destination rules for country-specific import restrictions and controlled substance permits.