of action . herbs main article: list of kampo herbs the 14th edition of the japanese pharmacopoeia (jp, nihon yakkyokuhō) lists 165 herbal ingredients that are used in kampō medicines. lots of the kampō products are routinely tested for heavy metals, purity, and microbial content to eliminate any contamination. kampō medicines are tested for the levels of key chemical constituents as markers for quality control on every formula. this is carried out from the blending of the raw herbs to the end product according to the ministry's pharmaceutical standards. medicinal mushrooms like reishi and shiitake are herbal products with a long history of use. in japan, the agaricus blazei mushroom is a highly popular herb, which is used by close to 500,000 people. in japan, agaricus blazei is also the most popular herb used by cancer patients. the second most used herb is an isolate from the shiitake mushroom, known as active hexose correlated compound. outside japan in the united states, kampō is practiced mostly by acupuncturists, chinese medicine practitioners, naturopath physicians, and other alternative medicine professionals. kampō herbal formulae are studied under clinical trials, such as the clinical study of honso sho-saiko-to (h09) for treatment of hepatitis c at the new york memorial sloan-kettering cancer center, and liver cirrhosis caused by hepatitis c at the ucsd liver center. both clinical trials are sponsored by honso usa, inc., a branch of honso pharmaceutical co., ltd., nagoya, japan. one of the first sources showing the term "kampō" in its modern sense (james curtis hepburn: a japanese and english dictionary; with an english and japanese index. london: trübner & co., 1867, p. 177.)