Kampo: Japanese herbal medicine

Kampo means “method of the Han” and refers to its Chinese origin. Chinese medicine reached Japan from the fifth and sixth centuries, via Korea and directly from China, together with Buddhism and Chinese writing.

The oldest surviving Japanese medical work is the Ishinpō, compiled in 984 by the court physician Tanba no Yasuyori. In the Edo period (1603–1868) Japanese physicians developed a practical form of their own. The school of “ancient formulas”, with physicians such as Yoshimasu Tōdō, went back to the Shanghan Lun and emphasised what the physician himself observes.

In 1874 the Meiji government decreed that new physicians had to study Western medicine. As a result Kampo was pushed aside. A small group of physicians kept the knowledge alive, and in the twentieth century a revival followed.

Kampo shares the basis of Chinese medicine, but is simpler and more practical. Instead of complicated theory, the “pattern” is central: the combination of signs that belongs to a particular formula.

A distinctive Japanese element is abdominal diagnosis, fukushin. The physician palpates the abdomen to feel tension, tenderness and resistance, and chooses a formula on that basis.

Kampo works with fixed formulas, which are prescribed as a whole and not adjusted for each patient.

In the Edo period Kampo was passed on in families and schools. From the eighteenth century European medicine also came in through the Dutch on Dejima, rangaku, and some physicians combined both.

After the Meiji reform only physicians who were already practising continued to use Kampo. Only after the Second World War did Kampo regain a place in training.

Today many Japanese physicians trained in Western medicine also prescribe Kampo. Since 2001 Kampo has been part of the medical curriculum.

The Ishinpō of 984 is the oldest Japanese medical work. It gathers knowledge from Chinese sources, some of which have otherwise been lost.

For Kampo practice, Zhang Zhongjing’s Shanghan Lun, from around 200 CE, is the most important classical work. Japanese physicians wrote many commentaries on it.

In the Edo period many Japanese works on formulas and abdominal diagnosis appeared.

In Japan Kampo is fully integrated into regular healthcare. In 1976 the first Kampo remedies were included in national health insurance; today 148 formulas are reimbursed.

Most Kampo is sold as standardised granules made by pharmaceutical companies. Many hospital doctors prescribe them, often alongside Western medicines.

There is a great deal of scientific research into Kampo in Japan.

Kampo formulas consist of a fixed combination of plants. A well-known formula is kakkontō, with kudzu, cinnamon, peony, liquorice, ginger, jujube and ephedra, used at the start of a cold.

Other frequently used plants are ginseng and bupleurum. Yokukansan is used in Japan for agitation in older people.

The plants come partly from Japan, but mostly from China.

In Japan Kampo is ordinary medicine. Kampo remedies have side effects too. A well-known example: the formula shōsaikotō, with bupleurum, was linked to pneumonitis, especially in combination with interferon.

Liquorice, present in many formulas, can raise blood pressure with long-term use. Ephedra strains the heart.