Kudzu vines grow rampant in the southern US, but it’s the root that is used as medicine (and in Japanese cooking)
An herbal pill taken before a binge reduced alcohol binges by 27%
STUDY: Santos GM et al, American Journal of Psychiatry 2026
STUDY TYPE: Randomized controlled trial
FUNDING: National Institute on Alcohol Abuse and Alcoholism
Background
Kudzu is an herbal remedy with a long history of use in China for alcoholism. It may work by making alcohol less rewarding, or it may make it more aversive, increasing hangovers with a mild disulfiram (Antabuse)-like effect (however, kudzu is not dangerous with alcohol like disulfiram is).
Research is slowly picking up in the US, with mixed results in six small trials. Today’s study is the largest to date, with a positive signal.
The Study
- 120 San Francisco adults with alcohol use disorder who binged at least weekly; 105 (88%) completed.
- Kudzu extract 2 g or placebo, taken 2.5 hours before an expected binge or during cravings, plus weekly brief counseling.
- 12 weeks of treatment, then a 3-month follow-up.
- Main outcome: binge-drinking days per week.
Results
Binge days fell from 2.2 to 1.4 per week on kudzu and barely changed on placebo (2.2 to 2.1), a 27% relative reduction (IRR 0.73). The benefit held 3 months after stopping (IRR 0.68).
By the final visit, 58% of the kudzu group still binged in a given week, compared with 81% on placebo.
Kudzu did not change total drinks, craving, or urine alcohol tests (EtG). The blood marker of heavy drinking (PEth) fell only in patients who took kudzu at least 2.7 days a week.
Side Effects
Side effects similar to placebo, but nausea was more common on kudzu (7 vs 2 patients).
Risks
None showed up in this study, but there are reports of liver toxicity, although kudzu protects the liver in animal models of alcoholic liver disease. Another possible risk is to the kidnesy: acute interstitial nephritis.
Limitations
- Drinking was self-reported; objective tests mostly showed no change.
- Patients with other severe substance use disorders were excluded.
Practice Implications
- Kudzu does not compete with first-line options for alcohol, like acamprosate, naltrexone, disulfiram, or even second liners like baclofen, topiramate, and gabapentin.
- Consider it for patients who don’t respond to other options and those who want an herbal alternative to disulfiram.
- Most studies used 520–750 mg of active isoflavones daily (divided BID or TID). This one adds a new strategy: 2 g of a standardized extract 2.5 hours before a party or happy hour. Products vary, so stick with clinically tested extracts. Find them and learn how to use kudzu in the Complementary and Alternative Medicine in Psychiatry Fact Book (at Amazon, or with CME credits and additional eBook at Carlat).
—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
