Rules for Carrying Medicines Across Borders
Travelling with medicines is usually straightforward, but a surprising number of trips go wrong at customs because a perfectly legal British prescription is treated very differently abroad. Painkillers containing codeine, ADHD medication, sleeping tablets and even some cold remedies can cause problems. Athletes face an extra layer of rules from anti-doping bodies. Our editorial team summarises what UK travellers need to know before packing their medicines.
Why medicines are regulated at borders
Every country decides for itself which substances are permitted, prescription-only or controlled. A medicine available over the counter in a British pharmacy may be prescription-only in one country and completely banned in another. Border controls exist to stop the trafficking of drugs with potential for misuse, but the rules apply equally to ordinary travellers.
The key distinction is between ordinary medicines and controlled drugs. In the UK, controlled drugs are those covered by the Misuse of Drugs Act 1971 and the Misuse of Drugs Regulations 2001, arranged into schedules. They include strong opioid painkillers, many benzodiazepines, stimulants used for ADHD, some sleeping tablets, medicinal cannabis products and anabolic steroids.
When you leave or enter the UK, you are subject to two sets of rules: British export and import law, and the law of the destination or transit country. Compliance with one does not guarantee compliance with the other.
The most common mistake is assuming that "it's on prescription, so it must be fine". A prescription demonstrates legitimate medical use but does not override a foreign ban.
Leaving and returning to the UK
According to Home Office guidance, you can carry controlled drugs prescribed to you in your hand luggage, but you need a personal import/export licence if you are carrying a supply that will last three months or more. Applications should be made well in advance — the Home Office asks for at least ten working days — and require a letter from the prescribing doctor.
For shorter trips, a licence is generally not needed for UK purposes, but a letter from your prescriber is strongly recommended. It should state your name, travel dates, the destination, the drug names, strengths and total amounts.
Useful documents to carry include:
- the medicine in its original pharmacy packaging with the dispensing label;
- a copy of your prescription or an NHS repeat prescription slip;
- a signed letter from your GP or specialist, ideally translated for non-English-speaking destinations;
- a Home Office licence where required, and any foreign permit the destination country demands.
Never carry medicines for another person, and keep the quantity reasonable for the length of your trip. Large amounts of any medicine may be interpreted as intent to supply.
Destination and transit countries
The UK government advises contacting the embassy or high commission of each country you will visit or transit through. Some destinations require advance permits for medicines that are routine in Britain.
| Medicine type | Examples | Where problems are common |
|---|---|---|
| Codeine-containing painkillers | Co-codamol, some cold remedies | United Arab Emirates, Japan, Indonesia |
| ADHD stimulants | Methylphenidate, lisdexamfetamine | Japan (amphetamines banned), UAE, Singapore |
| Benzodiazepines and Z-drugs | Diazepam, zopiclone | UAE, Qatar, Indonesia |
| Pseudoephedrine | Decongestants | Japan, Mexico |
| Cannabis-based medicines | Prescribed CBMPs | Most countries outside Europe; many within |
The table is indicative only; rules change, and travellers must check current requirements with the relevant embassy before departure.
Within the Schengen area, people carrying medicines that contain narcotic or psychotropic substances can use a Schengen certificate, valid for up to 30 days, issued by the authorities of the country of residence. For UK residents travelling to Schengen states after Brexit, embassy guidance and a prescriber's letter remain the main route.
Penalties abroad can be severe. Some countries have imprisoned travellers for carrying small amounts of prescribed medicines without permits.
Readers frequently ask us about Anabolic Steroids in Japan.
At the airport
Essential medicines should travel in hand luggage, in case checked bags are lost or delayed. Liquid medicines above 100 ml are permitted through security in the UK if they are needed during the flight, but you may be asked for proof such as a prescription or doctor's letter.
Injectable medicines such as insulin, adrenaline auto-injectors and biologics require sharps to be declared. Insulin must not be placed in the hold, where it may freeze; insulated pouches help in hot climates. Ask the airline in advance about carrying sharps and needle disposal containers.
Time-zone changes matter for medicines taken at fixed times, such as insulin, anti-epileptics or contraceptives. Discuss a dosing schedule for long-haul flights with your doctor or pharmacist before you travel.
Special considerations for athletes
Athletes in drug-tested sport must think about anti-doping rules as well as customs law. A medicine legal in both countries may still be prohibited in competition. If you need a prohibited substance for a genuine medical condition, you must hold a valid Therapeutic Use Exemption (TUE) from UK Anti-Doping or your international federation, depending on your level.
Buying medicines abroad is risky. Foreign brands of familiar medicines can contain different or additional ingredients, such as pseudoephedrine in a cold remedy, and labels may be in an unfamiliar language. Products bought from gyms or unlicensed sellers may be counterfeit.
Anabolic steroids, peptides and SARMs deserve a clear warning. Anabolic steroids are Class C controlled drugs in the UK; importing them by post, courier or freight is illegal, and many countries treat possession as a serious criminal offence. SARMs and many peptides are not licensed medicines anywhere for performance use. All are prohibited under the World Anti-Doping Code.
Team doctors and national governing bodies usually provide travel medicine guidance before international events. Using these resources is far safer than relying on internet forums.
Editorial team's conclusions
Travelling with medicines is safe and legal for most people, provided they prepare. Keep medicines in original packaging, carry a prescriber's letter, check whether a Home Office licence is needed for controlled drugs, and research rules in every destination and transit country. Athletes must also consider anti-doping regulations and hold a TUE where required. When in doubt, ask your pharmacist or the relevant embassy before you fly.
You may also find it useful to read our guides on how Therapeutic Use Exemptions work in the UK, which common cold and flu remedies are prohibited in sport, and the legal status of anabolic steroids in Britain.
References
- Home Office. Travelling to or from the UK with medicine. London: UK Government; guidance (accessed 2026).
- Misuse of Drugs Regulations 2001. SI 2001/3998. London: The Stationery Office; 2001.
- World Anti-Doping Agency. International Standard for Therapeutic Use Exemptions. Montreal: WADA; current edition.
- World Anti-Doping Agency. World Anti-Doping Code 2021. Montreal: WADA; 2021.
- International Narcotics Control Board. Guidelines for national regulations concerning travellers under treatment with internationally controlled drugs. Vienna: United Nations; 2003.
