Butea Superba (Red Kwao Krua) is a herb from Thai medicine sometimes thought to be the male equivalent of Pueraria Mirifica, a phytoestrogen known as White Kwao Krua; evidence for Butea Superba for these claims is lacking.
Butea Superba is most often used for
Butea Superba is a tuber vegetable that looks visibly similar to Pueraria Mirifica yet appears to be opposite in effect. This tuber has traditionally been used for the enhancement of male vitality and as an aphrodisiac in Thailand, and appears to be a source of androgenic compounds.
When studies investigated the androgenic effects, there appears to be the classical signs of direct androgenic activation (particularly, an increase in liver enzymes in some studies and growth of male sex organs; a decrease in testosterone levels in serum has been noted possibly due to negative feedback) but unlike its sister herb (Pueraria Mirifica) the bioactives mediating these androgenic effects are not currently known nor are their potencies relative to testosterone known.
Low doses of Butea Superba appear to be safe for human consumption, based on limited evidence, although higher doses have been connected to mutagenicity in mice (300-1000mg/kg, a human equivalent of 48mg/kg or above) and as such are not advisable.
Both studies on Butea Superba and its erectogenic effects appear to have their flaws, so although this herb could potentially be an erectogenic aid it is currently not proven to do so.
There is not enough information to recommend supplementation of butea superba, but it appears to be traditionally used in the range of 100-250mg. The exact bioactives that underlie its effects are not known