Pueraria is a genus of plants in the legume family (Fabaceae) that includes species like Pueraria mirifica (often called White Kwao Krua) and Pueraria lobata (kudzu). In traditional medicine—especially in parts of Southeast Asia—these plants have been used for decades for various purposes, including menopausal symptoms, hormonal support, rejuvenation, and more. But what does scientific research actually show, and how safe is Pueraria?
Scientific Evidence: What Studies Have Found
1. Animal Studies / Toxicity
- A 2013 study tested flower extract of Pueraria thomsonii (a kudzu relative) in mice and rats (acute & subchronic toxicity). Results: even high doses (up to ~5 g/kg body weight in mice, and up to 5% in diet for rats over 90 days) did not produce deaths or observable toxicological changes. Wiley Online Library+1
- Another study on Pueraria lobata (“kudzu”) vine ethanol extract over 4 weeks across different age-groups of mice showed no significant negative effects on body/organs, blood chemistry, or bone mineral density. J-STAGE
- On the flip side, Pueraria tuberosa (a different species) showed hepatotoxicity in rats at higher doses: elevated liver enzymes, cell damage in liver tissue, and signs of oxidative stress. PubMed
2. Human / Clinical Trials
- Pueraria mirifica has been tested in postmenopausal women: in a randomized, double-blind, placebo-controlled trial (24 weeks), doses of 20-50 mg/day showed some estrogen-like effects (on bone turnover, lipid profile) but no significant adverse effects on endometrium, breast tissue, liver, or kidneys. PubMed
- Another trial in perimenopausal women using 50-100 mg/day for six months found improvements in menopausal symptoms (hot flashes, night sweats, etc.), though some subjects had mild negative effects like changes in liver profile or anemia. PubMed
Risks, Side-Effects, and Unknowns
- Hormone-related activity: Pueraria species contain phytoestrogens. That means they can mimic some estrogen effects in the body. For people with hormone-sensitive conditions (e.g. estrogen-receptor positive breast cancer, endometriosis), there is a theoretical risk. Healthline+2Verywell Health+2
- Liver concerns: As noted, some studies (e.g. Pueraria tuberosa) show possible liver damage at high or prolonged doses. Also, in human trials, mild changes in liver profile were sometimes reported. PubMed+1
- Reproductive effects: In rat studies, high doses of Pueraria mirifica were associated with changes in uterine weight and testicular weight (depending on sex), and in female mice, some hematological changes at higher doses. Lower doses seemed safer. li01.tci-thaijo.org+1
- Limited long-term safety data in humans: Most studies are short to medium term (weeks to months). Very few long-term studies exist, and those that do often involve modest sample sizes.
Myths & Misconceptions
- There is no credible evidence that Pueraria kills hundreds of people per year in the way that very toxic foods or plants might, as some sensational articles claim.
- Many claims come from misunderstanding of dose: toxic effects in animals often occur at very high levels that humans are unlikely to consume in typical supplement use.
- Also, “natural” does not always mean safe — but risk depends heavily on dose, preparation, duration, and individual health status.
Practical Advice / Recommendations
- If you are considering using a Pueraria supplement, consult a healthcare provider, especially if you have hormone-sensitive conditions, liver disease, or are pregnant/breastfeeding.
- Use trusted sources: quality of supplement matters (purity, standardization).
- Start with low doses; avoid long-term use unless under supervision.
- Watch for potential side effects: gastrointestinal discomfort, changes in menstrual cycle, liver markers, etc.
Conclusion
Pueraria has shown promising effects in animal and human studies for things like menopausal symptoms, bone health, lipid profiles, etc. But, while evidence generally points toward safety at low to moderate doses over weeks to months, there is no scientific support for claims that it is among the world’s deadliest foods or that it kills large numbers of people every year. Any serious risk would likely come from extremely high doses, poor quality products, long-term use, or in vulnerable individuals.
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