On April 26, 2024, Japan’s authoritative newspaper Yomiuri Shimbun reported that the well-known drug Seirogan, produced by Kyokuto Pharmaceutical Industrial Co., was found to contain active ingredients below approved standards due to cost-cutting measures. The report, citing the Toyama Prefectural Government where Kyokuto is based, revealed that inspectors discovered a severe discrepancy between the drug’s claimed efficacy and its actual composition during a surprise inspection. To cover this up, Kyokuto had been falsifying experimental data for the past 30 years, allowing the drug to pass inspections and remain on the market.
As a result, the Toyama Prefectural Government invoked Japan’s Pharmaceutical and Medical Device Act, ordering Kyokuto to cease operations starting April 30. The suspension includes a 23-day halt in pharmaceutical manufacturing and a 22-day sales ban. Additionally, the company must submit a corrective action plan within a month from April 26, including measures to prevent future occurrences. Kyokuto’s management pledged to deal with the matter seriously and thoroughly investigate the incident to prevent recurrence.
Seirogan has a long history. According to Kyokuto’s official website, the drug dates back over 100 years. Its origins can be traced to the First Sino-Japanese War, during which many Japanese soldiers suffered from a mysterious illness now known as beriberi. Symptoms included fatigue, swollen feet, immobility, and ultimately paralysis or death. At the time, Japanese military doctors, including famed writer and army physician Mori ōgai, misdiagnosed the condition as a bacterial infection due to limited medical knowledge. On the eve of the Russo-Japanese War, a new pill made from wood creosote appeared—dubbed "Mokuyuyugan." Mori ōgai believed it could cure beriberi.
During the war, the drug was renamed "Seirogan," literally meaning “Conquering Russia Pill,” symbolizing Japan's hope to defeat Russia with the aid of this treatment. Each soldier was issued around 600 pills. However, it later became clear that Seirogan was ineffective against beriberi, which was actually caused by a vitamin B1 deficiency due to a poor diet, not a bacterial infection. Around 27,000 soldiers died directly or indirectly from beriberi during the war—nearly half of all combat deaths.
Despite its failure to treat beriberi, soldiers discovered Seirogan was effective in treating diarrhea and other digestive issues. After Japan's victory over Russia in 1905 and subsequent colonial expansion, the drug gained popularity in households across Japanese territories. Following World War II, perhaps to avoid antagonizing the Soviet Union, the name was changed from “Conquering Russia Pill” (征露丸) to “Seirogan” (正露丸), and its association with beriberi was dropped, officially becoming a gastrointestinal medicine.
Seirogan’s active ingredients include wood creosote, gambir powder, phellodendron bark powder, licorice powder, and dried tangerine peel powder. Excipients include calcium carboxymethyl cellulose, glycerin, water, and cinnamon powder. The key active component is wood creosote, a yellowish oily liquid with a strong odor, derived from heating and distilling wood such as beech or pine. It contains phenolic compounds and is known for inhibiting water secretion in the intestines and promoting water absorption. Thus, it is widely used to treat diarrhea, abdominal pain, poor appetite, indigestion, nausea, and vomiting—earning its reputation as a household “miracle cure” for diarrhea.
This data falsification scandal has once again undermined public confidence in the quality of Japanese-made products. It has drawn comparisons to another major incident in March 2024 involving Kobayashi Pharmaceutical. On March 22, the company disclosed that some consumers developed kidney problems after consuming its red yeast rice health supplements. Although reports of side effects had surfaced as early as January, they were ignored.
By March 26, Japanese media reported two deaths linked to these supplements. As of April 4, five deaths and 196 hospitalizations were confirmed. On April 5, Kobayashi announced that among 88 red yeast rice batches produced in the previous year, 34 were used in supplements—10 of which were contaminated with citrinin, a toxic compound produced by mold.
On April 19, Japan’s Ministry of Health, Labour and Welfare revealed that some batches also contained at least two unidentified substances. Further tests confirmed citrinin as the cause of the kidney damage. Citrinin is a stable toxin even at high temperatures and likely entered the product during fermentation when contaminated with Penicillium mold. As of September 9, 2024, the contaminated supplements had caused 391 deaths and 2,426 medical cases. On March 12, 2025, Kobayashi announced it had discarded approximately 416,000 units of the affected products.
Aside from Kyokuto’s Seirogan and Kobayashi’s red yeast supplements, other pharmaceutical scandals have plagued Japan in recent years. In 2019, Kobayashi’s eye wash was banned in Canada for containing aminocaproic acid, which can cause visual changes, dizziness, and nausea. In 2020, Ikeda Mohando recalled 7.75 million bottles of “Anpanman” children’s cough syrup due to insufficient quality checks. In 2021, Kobayashi Chemical was found to have mistakenly used the sedative rilmazafone instead of the antifungal itraconazole in a batch of medication—resulting in overdoses, car accidents, and two deaths.
Further investigation revealed that over 400 out of 500 drug products from Kobayashi Chemical had falsified production records spanning over 40 years, with full knowledge and tacit approval from management. The company was shut down for 116 days by local authorities.
These scandals have torn away the veil covering the myth of “Made in Japan” quality, exposing harsh realities. It's a wake-up call for the so-called Japanese “craftsmen” to reevaluate their integrity and commitment to safety.
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