Kudzu

What is kudzu?

Kudzu is a fast-growing vine native to East Asia and well known in the southern United States as an invasive plant. Its root (Ge Gen) and flower (Ge Hua) have long histories in traditional Chinese medicine. Both contain isoflavones, plant compounds such as puerarin and daidzein that have a structure loosely similar to estrogen. Supplements may use the root, the flower or both, and labels do not always say which.

What the research says

Alcohol intake

Most human research on kudzu concerns drinking behavior, and it used root extracts. In a study of heavy drinkers, a week of kudzu extract reduced the number of beers people drank in a laboratory setting, without changing their reported urge to drink (Lukas et al., 2005). In another small trial, a single 2 g dose of kudzu extract containing 520 mg of isoflavones, taken 2.5 hours before a drinking session, cut beer consumption compared with placebo in 20 men (Penetar et al., 2015). These studies are small and short.

Blood sugar

Kudzu flower extract increased glucose uptake in muscle cells in the laboratory (Lertpatipanpong et al., 2020). Cell studies like this are an early step and do not show an effect in people.

Brain and cognition

Some brain formulas say kudzu flower supports “glucose uptake in brain tissue.” We found no human trials of kudzu flower on memory, attention or mental performance, so this claim is not supported by clinical evidence. It is also worth knowing that the root and the flower differ in their isoflavone content, so results from root extracts in alcohol studies cannot simply be applied to a flower extract in a brain formula.

How it’s used in supplements

Kudzu root is sold for moderating alcohol intake and as a hangover remedy, and kudzu flower appears in some liver, metabolic and brain blends. The doses studied in people were measured in grams of root extract, which is likely more than most multi-ingredient blends contain, though blends rarely say. If you are considering kudzu to help cut back on drinking, talk with a doctor, because effective medical and behavioral treatments for alcohol use exist and kudzu research is still small.

Short-term studies did not report notable side effects. Because kudzu isoflavones have weak estrogen-like activity, people with hormone-sensitive conditions, or who take hormone therapy or tamoxifen, should talk with their doctor first. Because laboratory work suggests effects on glucose handling, people taking diabetes medicines should also ask before using it. It is not recommended during pregnancy or breastfeeding.