Checked against Japan Customs and Ministry of Health, Labour and Welfare (MHLW) official pages on 14 September 2026. Rules for specific medicines can change, so confirm your own prescription against the current MHLW guidance before you pack it.

Most travelers pack their regular medicine without a second thought and never hear from Japanese customs about it. Japan does let visitors bring in personal-use medicine, and for the vast majority of prescriptions, there’s no paperwork required at all. The part that catches people off guard isn’t the general rule — it’s that a small number of everyday prescriptions, including some common ADHD and allergy medications, aren’t just restricted in Japan. They’re treated as controlled stimulants, full stop, and a foreign prescription doesn’t change that.

Most medicine just needs to stay under a quantity limit — no certificate needed

Japan Customs sets specific thresholds for what a traveler can bring in without any prior paperwork. For prescription drugs and other medicines classified as poisonous or deadly poisonous substances, that’s up to a one-month supply. Injectable medicines and pre-filled syringes follow the same one-month limit. Other drugs and quasi-drugs — most over-the-counter items — get a two-month allowance, and external-use medicines (ointments, patches, and the like) are capped at 24 units per item. Contact lenses follow the two-month rule as well. Stay within these limits and you don’t need to apply for anything in advance; just be ready to explain what you’re carrying if customs asks.

Going over the limit means applying for a Yunyu Kakunin-sho before you fly

If your supply runs longer than these thresholds — a common situation for anyone on a months-long course of medication — you need an import certificate called a Yunyu Kakunin-sho (輸入確認書), still widely referred to by its older name, Yakkan Shoumei. This has to be obtained before you leave for Japan; it isn’t something you can sort out at the airport. MHLW’s guidance points travelers to apply through the online Import Confirmation system, and the general advice is to start the process at least two weeks ahead of departure, since regional health bureaus need time to review the application.

Medical psychotropic drugs get their own version of this rule: MHLW guidance allows carrying up to a one-month supply, or 2,160 mg, whichever is lower, without a certificate. Go over either number and you need the same import confirmation. Even within the no-certificate limit, MHLW recommends carrying a copy of your prescription or a doctor’s letter for any psychotropic or injectable medication, in case you’re asked to show why you need it.

A handful of common prescriptions are treated as banned stimulants — no exceptions

This is the part that trips up travelers who assume “I have a valid prescription” settles the question. Japanese law classifies certain substances as stimulants (覚醒剤) or their raw materials, and those are prohibited from import by private individuals outright — the only route in is a specific patient-use approval issued in advance by a Regional Bureau of Health and Welfare, not a routine doctor’s note. Amphetamine- and methamphetamine-based ADHD medications, including Adderall and Vyvanse, fall into this category. So do some common cold and allergy medicines built around pseudoephedrine, the active ingredient in products like Sudafed. A foreign prescription for any of these doesn’t create an exception — Japan Customs is explicit that a doctor’s prescription from abroad does not by itself authorize import of a prohibited stimulant.

If you’re on one of these medications, the practical options are to check with your doctor about an alternative formulation before you travel, or to go through the same Regional Bureau of Health and Welfare approval process well in advance — not to assume it’ll be fine because it’s legal and prescribed at home.

A quantity violation risks confiscation; a banned substance risks arrest

Bringing in a quantity over the customs threshold without a certificate risks confiscation at the airport — inconvenient, but recoverable. Bringing in a substance that’s flatly prohibited, like a stimulant-classified ADHD medication, is a different category of problem: Japan Customs and MHLW guidance both treat this as import of a controlled substance, which carries the same legal exposure as any other narcotics offense, regardless of intent or the traveler’s home-country prescription. The safest approach is to check your specific medication against the official lists before you pack, not after you land.

How Travel AI Rescue helps

Travel AI Rescue keeps Japan’s customs and health authority contact information one tap away, along with the nearest embassy or consulate line, so you’re not searching for the right office while standing at an arrival hall counter. It can display a Japanese-language card explaining your situation — “I’m carrying prescription medicine for personal use,” for instance — so customs staff understand you immediately even without a shared language. It also helps you put together a clear summary of what you’re carrying and why, drawing on a photo of your prescription or the doctor’s letter you’ve stored on the device, readable even with no signal. It works differently from a staffed consultation desk, and it’s with you around the clock — a bridge that gets you to the right window with the right information already prepared. (Whether a specific medicine requires an import certificate or is prohibited outright is determined by Japan Customs and MHLW, not by Travel AI Rescue.)

Sources

• Ministry of Health, Labour and Welfare, “Information for those who are bringing medicines for personal use into Japan.” https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/kenkou_iryou/iyakuhin/kojinyunyu/topics/tp010401-1_00001.html (accessed 14 September 2026).
• Japan Customs, “Q&A: Bringing pharmaceuticals, quasi-drugs, and cosmetics for personal use.” https://www.customs.go.jp/english/c-answer_e/sonota/9005_e.htm (accessed 14 September 2026).