Pueraria mirifica, also known as กวาวเครือ Kwao Krua (among other names), is a plant found in northern and north eastern Thailand and Myanmar.
In Thailand, the plant is known as “Kwao Krua Kao”, the ‘Kao’ meaning white which distinguishes Pueraria mirifica from other plants with tuberous roots also sharing the ‘Kwao Krua’ designation such as Butea superba, commonly called Kwao Krua Deng (Red) and the ‘black’ and ‘dull grey’ Kwao Krua plants. The species was definitively identified as Pueraria mirifica in 1952.
Dried and powdered, the tuberous root of Pueraria mirifica has a history of domestic consumption in Thailand in traditional folk medicine as a rejuvenating herb to promote youthfulness in both women and men and is used widely within the now government regulated practice of traditional Thai medicine.
Butea superba is a vining shrub native to Thailand, Vietnam, and India thought by locals to be an aphrodisiac among other effects. It is abundantly distributed in the Thai deciduous forest and has been popular among Thai males for its supposed effects on rejuvenation and sexual vigor. In English it has variously been called red kwao krua, creeping Butea superba, butea gum tree, flame of the forest, and climbing palas.
Existing open trials have come to conflicting conclusions about the efficacy of butea, though they used completely different products at different doses and in different populations. No placebo-controlled clinical studies exist so far to support aphrodisiac activity.