Japanese herbal medicine, known as Kampo, is part of the East Asian Chinese medicine tradition.  The word “Kampo” means “Han method,” a reference to Chinese culture of the Han era (206BC - 220AD).  Kampo is fundamentally a clinical system based on the classical medical literature dating back to the Han era.  Kampo is an older tradition preserved in Japan and based upon classical “TCM” (Traditional Chinese Medicine).  In Japan, Kampo has been in almost continuous use for centuries as a system of medicine with the exception of the Meiji era (1866 - 1912) when traditional medicine was banned.  It was during the Meiji era, however, when pharmacological research was first used to validate the use of the herb mao (Chinese ma huang; L. Ephedra sinica).  In 1885 Dr. Nagayoshi Nagai isolated the alkaloid ephedrine from this herb, frequently used in formulas for bronchial asthma and arthritis.  The pharmacological action of ephedrine was explained by Dr. Kinnosuke Miura in a German medical journal and ephedrine subsequently became a mainstream pharmaceutical for the treatment of bronchial asthma in Europe and North America as well.

Kampo is different from "Western-style" herbology, which uses individual herb or their standardized extraction, by mixing together multiple raw herbs, according to the ancient formulas, and then performing extraction on the mixture. The combination of the specific herbs and certain extraction processes creates a remedy most effective than the total of each herb extracted individually. To emphasize this, each Honso^® product label states the raw herb amounts as they are before the extraction process takes place.

Kampo was validated as a clinical system in the 20^th century.  By the late 1960s, in large part due to public demand, Kampo was integrated into the medical mainstream.  Today the large majority of physicians use at least some of the traditional formulas, which are available in almost all pharmacies by prescription, or under the advice of specially trained pharmacists.  The Japanese national health insurance plan covers the use of many of the traditional formulas. 

Hundreds of papers were published on the pharmacology of the herbs of the traditional pharmacopoeia even before the turn of the 20^th century, but in recent decades clinical and animal research has been undertaken on a large scale by university hospitals and private clinics throughout Japan.  Research in Japan has been more rigorous by western standards in the mold of conventional pharmaceutical research.  Japanese research on botanical medicine also uses substances that are pharmaceutical grade according to western standards.

Since 1994, Japanese manufacturers of traditional herbal medicines have been required to conform to the same standards of quality as other pharmaceutical companies.  This requires that all formulas are tested for any contaminants and are “standardized” for specific levels of key chemical constituents that are used as “markers” of plant quality.  This means that the herbs used in the formulas must have the required levels of at least two marker components in order for the formula to be approved as a medicament.  This places the onus for quality control on the herb importers for the Japanese manufacturers, because a single herb can have several “active” components and herbs grown in different climatic regions can have dramatically different chemical compositions.

What to read

Gale Encyclopedia of Alternative Medicine: Kampo medicine. By David Helwig

The Role of Traditional Herbal Medicine in Modern Japan. By Dan Kenner, LAc