When you’re travelling with medication—especially prescription or controlled drugs—a doctor’s letter can make the difference between a smooth airport experience and a stressful one.
The problem is this: there’s no single global standard. But there is a widely accepted format that most countries expect, and a handful of destinations that go further and require very specific wording or approvals.
This guide breaks it down clearly so you know exactly what to ask your doctor for—and where you need to go beyond a standard letter.
Why you need a doctor’s letter
A doctor’s letter (sometimes called a medical certificate or prescription letter) is used to prove that:
- The medication is prescribed to you
- It is for personal use
- The quantity you’re carrying is appropriate
This is especially important for:
- Controlled drugs (e.g. ADHD medication, strong painkillers)
- Injectable medication (e.g. EpiPens, insulin)
- Large quantities of medication
- Unusual or specialist treatments
Even when not legally required, having a letter can prevent delays, questioning, or confiscation.
What a standard doctor’s letter should include
This is where you don’t want to cut corners. A vague or incomplete letter can cause issues.
A proper travel letter should include:
Your Personal Details
- Full name (matching your passport)
- Date of birth
- Address (sometimes required)
Travel Details
- Dates of travel
- Destination(s)
This isn’t always mandatory, but many countries expect it—especially for controlled medication. This gives them an indication of how many days you plan to travel, and therefore they know roughly how much medication you should be carrying to cover you for that trip.
Medication Details
For each medication, the letter should clearly state:
- Name of the medication (both brand and generic if possible)
- Dosage (e.g. 20mg)
- Form (tablets, liquid, injection, etc.)
- Quantity you are carrying
- Frequency of use (e.g. twice daily)
Medical Justification
- The condition the medication is prescribed for
This doesn’t need to be overly detailed—but it must be clear the medication is necessary.
Prescriber Details
- Doctor’s full name
- Professional title
- Contact details (clinic address, phone number)
- Signature
A printed letter on headed paper is strongly recommended.
Extra details that strengthen your letter
These aren’t always required—but they can save you problems:
- Confirmation that the medication is for personal use only
- Statement that the medication is essential during the time of travel
- A note explaining if the medication contains a controlled drug
- A copy of the original prescription (carry this alongside the letter)
If you’re carrying injections or medical devices, include:
- Why they are needed
- Any equipment (needles, syringes, sharps containers)
Example letters for travelling with medication
Below are two doctors letters I have used when travelling. They are for different medications, and are totally different formats and include a huge difference in the amount of information they include. With my ADHD medication, a controlled substance, I have to ask for a new letter for each trip (it is very easy via my patient portal with the clinic). With Sylvie’s EpiPens letter we have used the same one since 2024 and never needed it to be updated.
If you plan to take a cruise, be aware that most of them have a medical form you need to fill out before you cruise with them. They will likely want a copy of these letters alongside their form so do some research and make sure you have given them everything they need before you leave.
How much medication can you travel with?
This varies by country, but a common rule is:
- Up to 30 days supply (strict countries)
- Up to 90 days (3 months) supply (more common)
Anything above this often requires:
- Special permission
- Import licences
- Additional documentation
Don’t assume – always check your destination. You can go a Google search for something like “bring codeine to Thailand” and look for an official-looking url, something like below:
With the top result, this is a website or blog. Helpful, but not official.
With the bottom result, this is the Thai Embassy in London. This information will be the most reliable in this situation.
If you scroll down further, you can see the moph.go.th – this is the Thai government website and therefore a really good resource for information about Thailand specifically. The Thai Embassy for Stockholm would also be a good place to look if no other official sites came up. Personally, I also like to read travellers real experiences on websites like Tripadvisor and Reddit too.
You can use this Google search method for almost every medication and every country – even if the search does not draw a government website for the place you will travel to, you could find a good forum post with links or emails that you can use to find the information you need.
Countries that require more than a standard letter
This is where people get caught out. Some countries have strict drug laws and do not accept a basic doctor’s letter alone.
Hong Kong
Hong Kong is a big one—and very relevant for travellers to Asia.
According to the Hong Kong Drug Office, requirements go beyond a standard letter for certain medications.
For controlled or “dangerous drugs,” you may need:
- Prior approval from the Drug Office
- An import licence for certain substances
- A detailed doctor’s letter including:
- Exact drug name and active ingredient
- Daily dosage
- Total quantity
- Duration of treatment
- Doctor’s full contact details
In some cases, travellers must submit documentation before travel for approval. For a full breakdown of the process, including how to apply for approval and what documents you’ll need, see my guide to bringing medication to Hong Kong.
This is especially important for:
- ADHD medication (e.g. stimulants)
- Strong painkillers
- Sedatives
Singapore
Singapore has strict drug laws and requires:
- Approval from the Health Sciences Authority for many controlled medications
- A detailed medical letter (similar to Hong Kong requirements)
You may need to apply online before travelling if you travel with specific medications. I’ve put together a detailed guide to bringing medication into Singapore, including approvals, paperwork and what to expect at the airport.
United Arab Emirates
The UAE requires:
- Pre-approval for many controlled medications via the Ministry of Health
- A doctor’s letter plus prescription
- Documentation uploaded in advance
Without approval, medication can be confiscated.
Japan
Japan is strict on certain medications (especially stimulants and some cold medicines).
You may need:
- A “Yakkan Shoumei” import certificate
- A doctor’s letter with full medication details
Punishment for bringing medication without the correct paperwork to Japan can be very harsh, do your research before you travel.
Common mistakes to avoid
This is where people go wrong:
- Carrying medication in unlabelled containers
- Not matching the name on the prescription to your passport
- Bringing too much medication without justification
- Assuming over-the-counter meds are always allowed
- Relying on a vague or handwritten note
If your medication is even slightly unusual—double check the rules.
Practical travel tips
If you want to avoid problems, do this:
- Keep medication in original packaging
- Carry your letter in your hand luggage
- Bring a copy of your prescription
- Check rules for every country (including layovers)
- Allow extra time at airport security
The bottom line
A doctor’s letter isn’t just a formality—it’s your proof, your protection, and sometimes your only defence if questions are raised.
Get it right, and most countries won’t give you a second glance.
Get it wrong, and you risk delays, confiscation—or worse.
If you’re travelling with anything beyond basic medication, don’t guess. Check the rules, get a proper letter, and if needed—apply for approval in advance. And for more information about travelling with an illness or disability, check my guide to disabled travel so you make the right steps to travel safely the first time.