Travelling with medicines: what to bring

If you fly from a United States airport

The Transportation Security Administration, the agency that screens passengers in the United States, has its own page on liquid medicines. Liquids are allowed in your carry-on bag up to 3.4 ounces, or 100 millilitres, and in checked baggage, and the agency allows larger amounts of medically necessary liquids, gels and aerosols in reasonable quantities for your trip, but you have to declare them to the officers at the checkpoint so they can inspect them.

The same agency's frequently asked questions say that all passenger items go through screening, that it is recommended to label your medication clearly so the screening goes faster, and that you may bring medically necessary liquids, medications and creams over 3.4 ounces in your carry-on bag, taking them out to be screened separately from the rest of your belongings.

For a child, there is a wider allowance. Formula, breast milk, toddler drinks and baby or toddler food, including puree pouches, in quantities over 3.4 ounces are allowed in carry-on baggage and do not have to fit in a quart-sized bag, because the agency treats them as medically necessary liquids. The same applies to the ice packs, freezer packs and gel packs that keep them cold, whether or not there is breast milk with them.

Two things are worth knowing there. Your child does not have to be with you to bring the formula, the breast milk and the related supplies. And the officers may need to test the liquids for explosives, so tell the officer at the beginning of the screening that you are carrying them, and take them out to be screened separately.

If you are entering the United States

The security rules are only the first of the two. U.S. Customs and Border Protection says that whether you are a U.S. citizen coming home or a foreign national visiting the United States, if you are travelling with any prescription or over-the-counter medication you have to comply with the laws the U.S. Food and Drug Administration enforces, and if the medicine is also a controlled substance you have to comply with the requirements of the Drug Enforcement Administration as well.

For a visitor who is not a U.S. citizen, the agency's advice is that you should have with you a valid prescription or a doctor's note written in English, and that the medication should be in its original container with the doctor's instructions printed on the bottle. If you do not have the original container, bring a copy of your prescription, or a letter from your doctor explaining the condition and why you need the medicine.

There is a limit on the amount. The page says you should travel with no more than you need for your personal use during your stay, and gives a rule of thumb: no more than a 90-day supply. If you are staying longer than 90 days, you may have additional medication sent to you by mail or courier, and you should be able to show the documentation that it is for your own use, which may include a copy of your visa and passport, a letter from your doctor, and a copy of your prescription in English.

If you are flying inside Europe

There is no single European rule for the medicines you carry across a border inside the European Union. The customs authority of one member state, the Swedish Customs, puts it plainly: different rules apply depending on the country you are travelling to or from, the rules differ from country to country even within the EU, and it is worth contacting the embassy of the country you are going to if you are not sure.

What that authority does set out is how its own country works. You can bring medicines in provided that they are intended for medical purposes and your personal use, and you have to be able to prove that they are for personal use, for example by presenting a prescription, a pharmacy label or a doctor's certificate. The amounts are counted by how long they last: a maximum of one year's consumption if you come from another country in the European Economic Area, and three months' consumption if you come from outside it. The European Economic Area is the EU countries plus Iceland, Norway and Liechtenstein.

For a medicine that is classified as a narcotic or as a doping substance, the same authority asks for the same proof of personal use, and says that in some cases you also need a Schengen certificate. That certificate has to name the prescribing professional, the person the medicine is prescribed to, and the dosage, and each preparation needs its own certificate. For a traveller leaving Sweden for another Schengen country, such as Denmark, Swedish Customs says the certificate can be obtained from a pharmacy.

When you cross the border with medicines for medical purposes and personal use that meet the rules, the Swedish customs authority tells you to choose the green or blue lane, the one where you have nothing to declare.

What an airline asks for

An airline's own rules are the airline's procedure, not the law of the country you are flying to or from, but they are what you meet at the gate. Avianca's own help centre says you can bring your medicines on the plane, that you must carry them in your carry-on baggage, and that you have to present your prescription or medical certificate during the security screening when it applies.

The airline asks for a prescription or a medical certificate when you carry insulin or other injectable medicines, syringes or needles, liquid medicines over 100 millilitres, controlled medicines, or medical devices you will use during the flight. The medicines must be for personal use, and if they are over 100 millilitres or are injectable, extra verification may be required.

One thing is worth saying out loud, because a family can plan around it. The airline's team is not authorized to help with the administration of medicines, to carry out medical procedures or to operate medical equipment during the flight. If your child needs a medicine at a set time, you are the one who gives it.

If the medicine needs to be kept cold

Avianca's page has a special case for these: you carry the medicine in your own portable cooler with gel packs or permitted dry ice, and the cooler has to fit under the seat in front of you. The airline cannot refrigerate or store medicines on board, so the cooler is the only way to keep it cold for the length of the flight.

Syringes and needles have their own rule on the same page: they must be in their original packaging and accompanied by your prescription or medical certificate, and if you use them during the trip the disposal is done at the airport, never on board the aircraft.

Plan ahead, with your doctor or pharmacist

Everything on this page is about what an authority asks for. The medicine itself is a question for your doctor or your pharmacist, and it is worth asking them before you travel: whether the medicine you need is available where you are going, and what happens if the flight is long or the connection is missed.

Then put the paper in your hand luggage, not in the checked bag: the prescription, the doctor's note in English if you are going to the United States, the pharmacy label, and the original containers. If you are travelling with a child, the papers for the child travel the same way.

Sources

• Official page of the Transportation Security Administration on liquid medications: in carry-on bags yes, with the limit of less than or equal to 3.4oz/100 ml, and in checked bags yes; TSA allows larger amounts of medically necessary liquids, gels and aerosols in reasonable quantities for your trip, but you must declare them to security officers at the checkpoint for inspection. The page was last updated on April 15, 2019 and says that the final decision rests with the TSA officer on whether an item is allowed through the checkpoint. — tsa.gov (checked 21 October 2026)
• Official frequently asked questions page of the same agency: all passenger items must undergo security screening, and it is recommended that medication be clearly labeled to facilitate the screening process; you may bring medically necessary liquids, medications and creams in excess of 3.4 ounces or 100 milliliters in your carry-on bag, and you must remove them from your carry-on bag to be screened separately from the rest of your belongings. — tsa.gov (checked 21 October 2026)
• Official page of the same agency on baby formula: in carry-on bags yes, with special instructions, and in checked bags yes; formula, breast milk, toddler drinks and baby or toddler food, including puree pouches, in quantities greater than 3.4 ounces or 100 milliliters are allowed in carry-on baggage and do not need to fit within a quart-sized bag, and they are considered medically necessary liquids; the same applies to breast milk and formula cooling accessories such as ice packs, freezer packs and gel packs, regardless of the presence of breast milk; your child or infant does not need to be present or travelling with you to bring breast milk, formula and related supplies; you must inform the TSA officer at the beginning of the screening process and remove the items to be screened separately, and TSA officers may need to test the liquids for explosives or concealed prohibited items; although not required, it is recommended that formula and breast milk be transported in clear, translucent bottles and not plastic bags or pouches, and screening will never include placing anything into the medically necessary liquid; TSA X-ray machines do not adversely affect food or medicines, but if you do not want the items to be X-rayed or opened you should inform the TSA officer, and additional steps will be taken and you or the travelling guardian will undergo additional screening procedures; travellers requiring special accommodations may request assistance through TSA Cares. The page was last updated on July 28, 2022. — tsa.gov (checked 21 October 2026)
• Official page of U.S. Customs and Border Protection on prohibited and restricted items, with a section on medication: whether you are a U.S. citizen returning from travel or a foreign national temporarily visiting the United States, if you are travelling with any prescription or over-the-counter medications you will need to comply with the laws and regulations enforced by the U.S. Food and Drug Administration, and if the medication is also a controlled substance you will also need to comply with the requirements of the Drug Enforcement Administration. For U.S. citizens: you should travel only with your own medication that was prescribed to you by a licensed physician and legally obtained in the United States, and in most cases it is illegal for a U.S. citizen to obtain drugs from outside the U.S. and import them for personal use, because drugs available in other countries, including foreign-made versions of drugs approved for use in the U.S., have not been evaluated or approved by the FDA. For non-U.S. citizens temporarily visiting the United States: you may be allowed to travel with your own medications, and in general you should have with you a valid prescription or doctor's note, written in English; the medication should be in its original container with the doctor's instructions printed on the bottle, and if you do not have the original container you should bring a copy of your prescription or a letter from your doctor explaining your condition and why you need the medication; you should travel with no more than you need for your personal use during your stay, and a rule of thumb is to bring no more than a 90-day supply; if you are staying longer than 90 days, you may have additional medication sent to you by mail or courier, and you should be able to provide documentation showing that the medication is being sent for your own use while visiting the United States, which may include a copy of your visa and passport, a letter from your doctor, and a copy of your prescription in English. The page also warns that the FDA prohibits the importation of fraudulent or counterfeit drugs and medical devices. — cbp.gov (checked 21 October 2026)
• Official page of the Swedish Customs, Tullverket, on travelling with medicines: different rules apply depending on the country you are travelling to or from and whether the medicine is classified as a narcotic or not, the rules differ from country to country even within the EU, and the rules of the Swedish Medical Products Agency apply to what applies when you are travelling with medicines and syringes, both to and from Sweden, with Swedish Customs checking at the border that the Medical Products Agency's rules are followed. As a traveller you can bring medicines into Sweden provided that they are intended for medical purposes and your personal use, and you must be able to prove that they are being imported for personal use, for example by presenting a prescription, pharmacy label or doctor's certificate. If you come from another EEA country you can bring a maximum of one year's consumption with you, and if you are from a non-EEA country the limit is three months' consumption, and the EEA includes all EU countries, Iceland, Norway and Liechtenstein. The page also says that if you are travelling from Sweden it is important to know that the rules differ from country to country, even within the EU, and to contact the country's embassy if you are unsure. In its questions and answers, for a traveller going from Sweden to another Schengen country such as Denmark, which is part of the Schengen area, it says you need to bring a certificate that you can obtain from a pharmacy, and that each preparation requires a separate certificate. For drugs classified as narcotics or doping substances you can only bring them in for medical purposes and personal use and you must be able to prove it, and in some cases you may also need a Schengen certificate, which must state the prescribing professional, the person for whom the medicine is prescribed, and the dosage, for example 2 tablets a day; each preparation requires a separate certificate. If you are carrying medicines for medical purposes and personal use that comply with the rules, you choose the green or blue lane, nothing to declare, when you cross the border into Sweden. — tullverket.se (checked 21 October 2026)
• Official help centre of Avianca on bringing medications on board, in the airline's own procedure and not a rule of any country: you can bring your medications on the plane, you must carry them in your carry-on baggage and, if applicable, present your prescription or medical certificate during the security screening; the medications must be for personal use, and if they exceed 100 ml or are injectable, additional verification may be required; the airline's team is not authorized to assist with the administration of medications, perform medical procedures or operate medical equipment during the flight. The permitted medications are tablets or capsules, syrups or liquids, which may exceed 100 ml if for medical use, and inhalers or medical aerosols; you need a prescription or medical certificate when carrying insulin or other injectable medications, syringes or needles, liquid medications over 100 ml, controlled medications, or medical devices you will use during the flight. On medicines that require refrigeration: carry them in your personal portable cooler with gel packs or permitted dry ice, it must fit under the seat in front of you, and the airline is unable to refrigerate or store medications on board. On syringes and needles: they must be in their original packaging and accompanied by your prescription or medical certificate, and if you use them during the trip, disposal must be done at the airport, never on board the aircraft. — ayuda.avianca.com (checked 21 October 2026)