Primary sources only. Where the official page disagrees with this one, it is right.
A Yunyu Kakunin-sho (輸入確認証, also written yakkan shoumei) is a confirmation from Japan's Ministry of Health, Labour and Welfare that the medicine you are carrying is for your own treatment and not for sale. It is not a licence to import a banned substance. It is a statement that your quantity is personal.
Below certain quantities, confirmation at customs on arrival is normally enough. You need the certificate when you exceed them:
• more than a one-month supply of a prescription medicine
• more than a two-month supply of a non-prescription medicine
• more than 24 items of any single product of an external-use product
This is the part that gets travellers arrested. Japan does not issue an import confirmation for substances it prohibits outright, and the prohibition covers medicines that are ordinary prescriptions or even over-the-counter products elsewhere. Stimulants and stimulant raw materials are the main trap: amphetamine-based ADHD medication and pseudoephedrine cold medicine both fall in this group, and no application, letter or declaration opens that door. The penalty for stimulants is imprisonment with work for up to 20 years and a fine of up to ¥5 million.
If your medicine is in that group, the certificate route is not a slower path to the same destination — it is a closed door. Read the specific page instead: Adderall · Sudafed and pseudoephedrine · CBD.
If you carry a narcotic or psychotropic medicine for your own treatment — not an excess quantity of an ordinary drug, but a controlled one — permission to import by carrying is handled by the narcotics control department of the regional health bureau, not by the ordinary import confirmation. Ask about your specific medicine before you assume which form applies.
Applications go through the ministry's online system at impconf.mhlw.go.jp. Questions go to yakkan@mhlw.go.jp. Apply at least one month before departure — processing can take up to four weeks, so a trip booked three weeks out is already too late for anything that needs the certificate.
The application asks what the product is, what is in it, how much you are bringing and when you are travelling. Have your prescription or a doctor's letter ready to attach, with the active ingredient named in generic form — the officer reading your file works from the ingredient, not the brand. Our doctor's letter template covers the fields that get asked for.
Carry the certificate with you on arrival. Not in checked baggage, not in an email you plan to open on airport wi-fi. The guidance is blunt about this: if it is required, you must have it with you when you arrive.
Ministry of Health, Labour and Welfare — import confirmation online system
MHLW — personal import of medicines
Yunyu Kakunin-sho guide, reproducing the MHLW quantity thresholds (PDF)
Tokyo Customs — narcotics, psychotropics and stimulant raw materials
Last checked 2 October 2026. Where the official pages above disagree with this one, they are right and we are out of date.