Butea Superba, a member of the Papilionoideae family, is a flowering plant growing primarily in the deciduous forested areas of eastern India and Thailand along the Kanchanaburi and Chiang Mai provinces. Butea superba has a climbing habit around large trees. It bears masses of blooms that range from a yellowish-orange to a vivid red. These softly textured blooms produce a yellow dye. It reproduces through root division and seeds, and its local name is Red "Kwao Krua Dang."
The flowers underground tuberous roots and some parts of its stems are used in Thai herbal preparations, according to a 2003 article in the Asian Journal Andrology. The preparations are for male erectile dysfunction and, Butea superba is anecdotally known as an herbal Viagra.
Aranya Manosroi published the results of a study of Butea superba in a 2006 "Fitoterapia" article. Manosroi notes that although Butea superba has been used in Thai folklore medicines for more than 100 years, when 360mg of the main constituent of the root (butenin) was injected into a rat, the rat died of cardiovascular system failure.
Because crude preparations of this root with uncertain dose ratios are readily available on the Thai market, Thai authorities have tried to protect consumers by proposing doses of 100mg per day. The results of the Manosroi study using five different dose sizes reflected a 16 percent increase in sperm count over the eight-week trial and in the largest dosage group in the study, a significant increase in the weight of the testes. This produced a finding that Butea superba caused an increased release of male sex hormone, which explains the plant's reputation for increasing sexuality in men.
Butea superba is not regulated by the United States FDA since it is regarded as an herbal supplement. This means that it can be sold in products of varying purity levels, doses, recipes and types. While Thai officials oversee Butea superba, it is important to consider that herbal supplements during the past few years have enjoyed a rapid growth in the United States. A 2007 article in the "Songklanakarin Journal of Science Technology" notes that the Thai herb products market grew 28 percent in 2004 with its main export country being the United States.
The irradiation of herbs to reduce microbacterial load is controversial. Phianphak's study detected high levels of staphylococcus, salmonella, coliform and fungi. Supplement products in the United States, according to Naturally Direct, do not have to be irradiated and in fact, they claim not to sell herbal products that are irradiated. Phianphak notes that herbs contaminated with pathogenic bacteria can result in serious food-borne illness. Butea superba plants were tested as part of the study.