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Legal aspects of marijuana use

Country report – Japan

By: Minoru Arakaki, M.D., Ph.D. (President, Japanese Clinical Association of Cannabinoids)Last update September 2018 


In Japan, hemp was a crop that could be grown freely by anyone from 10,000 years ago to before World War II. Hemp fibers were used to manufacture clothing, strings, and rope. Hemp stems were used as building materials for the roofs of traditional Japanese houses and as firewood. Hemp seeds were used as food and feed, leaves were used as fertilizer, and flowers were used for traditional Chinese medicine. Thus, hemp was used in diverse areas of life and no part of the plant was wasted. International trade had spread in Japan when the Meiji era began in 1868. At that time, the imported Indian cannabis was used as a medicine. Thus, Indian cannabis was listed in the Japanese Pharmacopoeia from 1886 to 1951 and was used to treat asthma and in sleeping pills.

During the period of occupation after World War II, the establishment of a law to control narcotics was instructed by the general headquarters (GHQ)/Supreme Commander for the Allied Powers (SCAP). However, the Japanese government decided to regulate cannabis separately from other narcotics. GHQ/SCAP had ordered to ban all kinds of cultivation and possession of cannabis; however, the cultivation and use of hemp was a necessity of life in Japan at that time. Therefore, in 1948, with the enactment of the Cannabis Control Act, hemp cultivation became a prefectural governor license system. Medical use of cannabis was banned by this act.

At the time of enactment of the Cannabis Control Act, there were 37,000 cultivators and about 4,000 hectares of cultivated area. However, with the advent of chemical fibers and the changing lifestyle, the demand for hemp decreased. This drastically reduced the number of cultivators. Currently, there are only 34 cultivators covering <10 hectares of cultivated area. On this cultivation scale, hemp products are used only for shrine religious ceremonies, traditional crafts and folk customs. Previous studies have reported that the variety of hemp grown in Japan is a variety called “fiber type,” which contains only small amounts of THC. Therefore, it was generally not used for medical treatment or for smoking as marijuana.

In the 1970s, under the influence of foreign hippie culture, >1000 individuals were arrested for possession of marijuana. In Japanese schools, cannabis is presented to be as dangerous as stimulants and synthetic drugs6. Today, there are 2,000–3,000 arrests related to marijuana per year. Occasionally, whether or not cannabis control is required is debated in court. However, the court has not passed any judgment to promote legal changes or to recognize the rights of patients using medical cannabis. The government is not considering a re-evaluation or review of the Cannabis Control Act based on scientific evidence regarding the medical effects of cannabis.

In the past, hemp was a crop that supported people’s livelihood. However, recently the number of marijuana-related arrests has increased. It has become a big topic frequently covered by the media. Thus, the bad image of the plant is consolidated8.

Legal summary

The Cannabis Control Act regulates certain parts of cannabis plants, regardless of the THC content. Leaves and flowers of cannabis plants are illegal; however, seeds and stems are legal. 

The act reads as follows:

There are two kinds of licenses defined in this act: The “cannabis cultivator” license and “cannabis researcher” license. The cannabis cultivator license is issued to farmers growing hemp to sell fibres and seeds. However, cannabis is regulated as a narcotic plant, and only few new licenses are issued. Cannabis researcher license is issued to the Narcotics Control Officer to control marijuana. Only few researchers have licenses for pharmaceutical research at the university.

Article 4 of the act prohibits both the prescription of cannabis by doctors and the use of cannabis by patients (see below). As a result, it is impossible to evaluate the efficacy and safety of cannabis in Japan in clinical studies. Punishment for possession is a maximum 5 years behind bars and illicit growers face 7-year sentences.

Current regulatory approach

The official view of the Japanese government is not known internationally. Therefore, below we present the most recent view as reported in the minutes of the Diet and the memorandum on questions. The most recent official view is published in the memorandum on questions of April 2016 conducted by the House of Councillor, Hiroyuki Arai.

The memorandum on questions is a document in which a Diet member sends questions to the cabinet as described in Article 74 of the National Assembly Act. The document is sent to the cabinet through the chairperson of the House to which the Diet member belongs. The cabinet that receives the document is required to reply in writing within 7 days. These answers, by of the Ministry of Health, Labour, and Welfare represent the official opinion of the Japanese government.

There were 9 items of questions on April 14, 2016, and 12 items of additional questions on June 1, 2016. The government response included 14 items, which are summarized below:

  1. Cannabis consumption has hallucinatory and harmful effects. Therefore, the use of cannabis as a medical product requires careful deliberation.
  2. The medical use of cannabis can be studied using synthetic THC. Therefore, there is no need to study natural cannabis.
  3. There is no understanding of the “right of patients” of the Lisbon Declaration.
  4.  WHO does not recognize the effectiveness cannabis for medical use. Therefore, deregulation in National Strategic Special Zones is difficult.

In addition, the Japanese government knows that the United States is conducting cannabis studies. Imported CBD oil cannot be inspected by government agencies. And, in general, the detailed view of the Japanese government is not very clear.



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