Summary
Pueraria candollei variant mirifica (shortened to Pueraria mirifica) is 1 of 3 herbs given the title of "kwao krua," and is known as white kwao krua. This herb has been traditionally used as a vitality enhancer and rejuvenating agent, particularly for older women. It should be considered a different supplement than kudzu root, Pueraria lobata.
This herb is a great source of classical phytoestrogens (including soy isoflavones), but it also contains a class of phytoestrogens known as chromenes that rival estrogen itself in potency. The herb is highly estrogenic as a result and is considered the standard herbal "estrogen replacement therapy" due to its potencies.
Pueraria mirifica has been tested numerous times for reducing menopausal symptoms (because estrogen replacement therapy itself is quite effective), and despite the universal promise it shows, many of the studies were not blinded and not compared against a placebo; on the topic of menopausal symptoms, this is a significant problem because a placebo can be very potent (see black cohosh as an example; the placebo effect in menopause has been reported to result in up to a 50% reduction in symptoms).
Based on the preliminary evidence, it does appear promising and effective for menopausal symptoms, but much more research is needed before it can be considered a main opinion. There is currently no evidence to support the notion that this herb is somehow safer than estrogen replacement therapy, so the benefits and risks should be viewed as interchangeable for the time being.
Dosage Information
For Pueraria mirifica (white kwao krua), a dose of 20 to 50 mg of root powder (not an extract) should be taken daily once in the morning. This amount appears to be significantly bioactive, and it would be advisable to not exceed this dosage.
Men who are looking for a antihangover supplement should consider Pueraria lobata (kudzu) instead, to avoid inadvertent estrogen effects from Pueraria mirifica.
