Drugs in Japan
Importing or bringing medicines from overseas is controlled by the Law on Securing Quality, Efficacy and Safety of Products including Pharmaceuticals and Medical Devices and by the Customs Law to prevent health hazards caused by defective products.
Some products that are available over the counter in other countries, such as cold and flu remedies, are banned in Japan, and possession of even small amounts of them is punishable by lengthy imprisonment. Also, Cannabis (marijuana) is strictly banned in Japan, although it is permitted in some countries.
Please visit The Ministry of Health, Labour and Welfare for further information if you wish to bring medicines for personal use into Japan. In addition, please visit for reference; https://jp.usembassy.gov/u-s-citizen-services/doctors/importing-medication/