Medical marijuana is not legal in Japan. Patients cannot possess, use, or import cannabis for medical purposes, and a prescription from a doctor in another country carries no weight under Japanese law. Japan amended its Cannabis Control Act in December 2024 to let pharmaceutical companies develop and seek approval for cannabis-derived medications, but that change did nothing for individual patients: no such medication has been approved, and personal possession and use remain criminal offenses carrying years in prison.1Japanese Law Translation. Cannabis Control Act
What Japanese Law Says About Cannabis
The Cannabis Control Act, enacted in 1948, prohibits anyone who is not a licensed Cannabis Handler from possessing, cultivating, receiving, or transferring cannabis. Importing and exporting are also banned, with a narrow exception for authorized researchers. The law covers the plant and all its products. Only mature stalks (excluding their resin) and seeds are carved out.1Japanese Law Translation. Cannabis Control Act
Enforcement does not distinguish between recreational and medical use. Authorities use drug-sniffing dogs, blood tests, and stop-and-frisk tactics, and even trace amounts can trigger an arrest.2U.S. Department of State. Japan Travel Advisory Foreign nationals face the same consequences as residents.
What the 2024 Amendments Changed, and What They Didn’t
On December 12, 2024, Japan amended both the Cannabis Control Act and the Narcotics and Psychotropics Control Act. The revised law lets pharmaceutical companies submit marketing approval applications to the Ministry of Health, Labour and Welfare (MHLW) for cannabis-derived medications. Approved THC-containing drugs would be classified as medical narcotics and dispensed only by prescription under the narcotics law. CBD-containing pharmaceuticals can now be developed without the restrictions that previously applied.
None of this means a patient can walk into a Japanese pharmacy and buy a cannabis product today. No cannabis-derived medication has received marketing approval in Japan. Epidiolex, a CBD-based drug used elsewhere for severe pediatric epilepsy, entered Phase 3 clinical trials in Japan in 2022, but the trial did not meet its endpoints. Further trials have reportedly begun following the 2024 amendments, with no timeline announced for approval.
The same amendments closed a longstanding gap in the law by making personal use of cannabis a criminal offense for the first time. Under the previous version of the Act, consumption itself was not explicitly illegal; only possession, cultivation, and transfer were. That loophole is gone. Using cannabis now carries up to five years in prison, and use motivated by profit carries up to seven.3Japanese Law Translation. Cannabis Control Act – Chapter VI Penal Provisions
Bringing Cannabis or a Prescription Into Japan
You cannot bring cannabis into Japan under any circumstances, including cannabis prescribed by a doctor in your home country. Japan Customs explicitly lists medicines manufactured from cannabis among prohibited imports, and a valid foreign prescription provides no legal protection.4Japan Customs. WARNING! Penal Provisions The U.S. State Department warns that Japanese law treats medical and recreational marijuana identically.2U.S. Department of State. Japan Travel Advisory Importing cannabis carries up to seven years in prison, even in small quantities for personal medical use.
Japan does have a permit process for travelers carrying other controlled medications, such as morphine-based painkillers or certain ADHD drugs. The MHLW Narcotics Control Department requires an import certificate obtained before arrival, a medical certificate from the prescribing doctor explaining the specific medical necessity, and documentation of the packaging.5Ministry of Health, Labour and Welfare. Application Guidance – Narcotics Control Department That process does not apply to cannabis in any form.
Where CBD Fits
CBD itself is not classified as a narcotic in Japan, but the allowable THC content is far stricter than almost anywhere else. Under the framework accompanying the 2024 amendments, maximum THC concentrations are:
- Oils, fats, and powders: 10 mg/kg (0.001%)
- Beverages and aqueous solutions: 0.10 mg/kg (0.00001%)
- All other products, including edibles, cosmetics, and raw materials: 1 mg/kg (0.0001%)
Any product exceeding these thresholds is regulated as a narcotic. The United States, by comparison, allows up to 0.3% THC in hemp-derived products — 300 times the Japanese limit for CBD oil. Many CBD products sold legally in other countries would be treated as illegal narcotics in Japan. Importing CBD legally also requires substantial documentation, including a certificate showing the product was made only from hemp stalks or seeds and laboratory analysis of its THC and CBD content.6USDA Foreign Agricultural Service. Japanese Import Regulations for Industrial Hemp Products Travelers carrying CBD without this paperwork risk confiscation and potential criminal charges.
Penalties if You’re Caught
Maximum sentences under the Cannabis Control Act are severe by international standards and apply equally to foreign nationals:3Japanese Law Translation. Cannabis Control Act – Chapter VI Penal Provisions
- Possession, receiving, or transferring: up to 5 years in prison.
- Personal use: up to 5 years in prison.
- Cultivation, import, or export: up to 7 years in prison.
- Any of the above for profit: up to 7 to 10 years, with fines up to ¥2 million to ¥3 million (roughly $12,500 to $19,000 USD).
These are maximums, but Japanese courts take drug offenses seriously and first-time offenders routinely receive prison time rather than suspended sentences. Japanese law also permits detention for up to 23 days before formal charges are filed, with limited access to a lawyer during that period.
Immigration Consequences, Including for Past Convictions Abroad
A cannabis-related conviction, whether in Japan or anywhere else, can bar you from entering Japan. Under Article 5 of the Immigration Control and Refugee Recognition Act, any foreign national convicted of violating a drug control law and sentenced to a penalty is denied permission to land. The provision covers narcotics, marijuana, opium, stimulants, and psychotropics, and applies to convictions under foreign laws.7Embassy of Japan in Los Angeles. Immigration Control and Refugee Recognition Act Article 5
Unlike other grounds for denial of landing, the drug-conviction bar carries no stated expiration. A marijuana possession conviction from years ago, in a country where cannabis is now legal, can still result in being turned away at the airport. The final decision rests with immigration officers at the port of entry.
Foreign nationals caught with cannabis inside Japan face deportation on top of the criminal penalties. A first deportation triggers a five-year ban on reentry, and a second extends the ban to ten years. Combined with the underlying drug-conviction bar, the practical outcome is often a permanent inability to visit Japan.