Kampō (or Kanpō, 漢方) medicine is the Japanese study and adaptation of Traditional Chinese medicine. The basic works of Chinese medicine came to Japan between the 7th and 9th centuries.  Since then, the Japanese have created their own unique herbal medical system and diagnosis. Kampo uses most of the Chinese medical system including acupuncture and moxibustion but is primarily concerned with the study of herbs.
Approved Kampo medicines
Today in Japan, Kampo is integrated into the national health care system. In 1967, the Ministry of Health, Labour and Welfare approved four kampo medicines for reimbursement under the National Health Insurance (NHI) program. In 1976, 82 kampo medicines were approved by the Ministry of Health, Labour and Welfare. Currently, 148 kampo medicines are approved for reimbursement.
Rather than modifying formulae as in Traditional Chinese medicine, the Japanese kampo tradition uses fixed combinations of herbs in standardized proportions according to the classical literature of Chinese medicine. Kampo medicines are produced by various manufacturers. However, each medicine is composed of exactly the same ingredients under the Ministry's standardization methodology. The medicines are therefore prepared under strict manufacturing conditions that rival pharmaceutical companies. The two leading companies making kampo medicines are Tsumura (ツムラ) and Kanebō (カネボウ).
Extensive modern scientific research in Japan has validated the effectiveness of kampo medicines. In October 2000, a nationwide study reported that 72% of registered physicians prescribe kampo medicines.
Herbs used in kampo medicines
The 14th edition of the Japanese Pharmacopoeia (JP) (日本薬局方 Nihon yakkyokuhō) lists 165 herbal ingredients that are used in kampo medicines.
Tsumura (ツムラ) is the leading maker of kampo medicine. They make 128 of the 148 kampo medicines. The most common herb in kampo medicine is Glycyrrhizae Radix (Chinese liquorice root). It is in 94 of the 128 Tsumura formulae. Other common herbs are Zingiberis Rhizoma (ginger) (51 of 128 formulae) and Paeoniae Radix (Chinese peony root) (44 of 128 formulae).
Kampo outside Japan
In the United States, kampo is practiced mostly by acupuncturists, Chinese medicine practitioners, naturopath physicians, and other alternative medicine professionals. Kampo herbal formulae are studied under clinical trials, such as the clinical study of Sho-saiko-to (H09) for treatment of hepatitis C at New York Memorial Sloan-Kettering Cancer Center and liver cirrhosis caused by hepatitis C at UCSD Liver Center. Both clinical trials are sponsored by Honso USA, Inc., a branch of Honso Pharmaceutical Co., Ltd., Nagoya, Japan.
- Wen, Dan. "Sho-saiko-to, a Clinically Documented Herbal Preparation for Treating Chronic Liver Disease". HerbalGram: The Journal of the American Botanical Council, Issue: 73 Pages: 34–43, 2007.
- Rister, Robert. Japanese Herbal Medicine: The Healing Art of Kampo. Avery, 1999. (ISBN 0-8952-9836-8)
- Tsumura, Akira. "Kampo: How the Japanese Updated Traditional Herbal Medicine." Japan Publications, 1991. (ISBN 0-8704-0792-9)
- Shibata, Yoshiharu and Jean Wu. "Kampo Treatment for Climacteric Disorders: A Handbook for Practitioners." Paradigm Publications, 1997. (ISBN 0-9121-1151-8)
- Research in Japanese Botanical Medicine and Immune Modulating Cancer Therapy - Kampo, Townsend Letter for Doctors and Patients, August 2001, by Dan Kenner, Ph.D.
- Complementary Medicine: The Yin and the Yang: Two Party System for Healing by Alan Glombicki, MD, Associate Professor of Clinical Medicine, University of Texas, Houston, TX
- Treating Chronic Liver Disease with Kampo Formula Sho-saiko-to by Dan Wen, MD, Phoenix, Arizona.
- Europäische Akademie für Kampomedizin