Pueraria mirifica, also known as kwao kruea khao, is an herb found in Thailand and used in supplements because of its promise in the field of beauty enhancement. Pueraria mirifica advertisements typically promote it as a supplement to enhance breast size. Its side effects are generally mild and may not even occur after ingestion.
Pueraria mirifica contains high levels of a substance known as phytoestrogen, which is similar to the female hormone, oestrogen. Concentrated doses of phytoestrogen induce changes in the body typically associated with oestrogen, such as breast enlargement.
Pueraria mirifica is available in several forms, including pills, which contain 80 to 1,000 milligrams of pueraria mirifica per dose. How many milligrams you take depends on how quickly you want results---the higher the dosage, the faster the results. According to the Pueraria Mirifica Revealed website, you should not take more than 1,000 milligrams of pueraria mirifica a day for longer than six months.
While pueraria mirifica is a natural substance, people should talk to their doctor before using it. A doctor may have further insight into the exact effects and reliability of pueraria mirifica, especially as it pertains to an individual's body type and general health.
According to the U.S. Department of Health and Human Services, the only side effect of pueraria mirifica occurred in women sensitive to estradiol, a predominant female sex hormone, resulting in headaches after use. However, a 2004 study by the Department of Obstetrics and Gynecology at Hat Yai Regional Hospital in Songkhla, Thailand, found that some women experienced short-lived anaemia after taking pueraria mirifica. This study involved 37 pre- and post-menopausal women---experiencing symptoms such as hot flushes and night sweats---given 50 to 100 milligrams of pueraria mirifica per day and monitored for six months. Despite the reports of anaemia, pueraria mirifica reduced negative symptoms overall.
Women currently taking birth control pills should consult their health care provider before taking pueraria mirifica, to avoid potential interactions that could affect the efficacy of their medication. According to PuerariaHerb.com, taking pueraria mirifica may cause spotting as well as early or delayed periods, which "is very safe and normal."