Kudzu extract taken before heavy drinking cut binge days in a placebo-controlled trial

A UC San Francisco study published in the American Journal of Psychiatry on 4 November 2026 tested whether an extract of kudzu, a plant used in East Asian traditional medicine, can help people binge drink less.

The study

• Type: randomised, placebo-controlled trial.
• Participants: 120 adults with alcohol use disorder who binge drank at least once a week (5+ drinks on one occasion for men, 4+ for women).
• Intervention: half received a standardised kudzu extract, half a placebo, taken about 2.5 hours before they expected to drink heavily, for 12 weeks. Both groups also had brief weekly counselling.

Results

• Binge-drinking days fell from 2.15 to 1.42 per week with kudzu, versus 2.15 to 2.06 with placebo.
• The share of weeks with any binge drinking fell from 88% to 58% with kudzu, versus 88% to 81% with placebo.
• Three months after treatment ended, the kudzu group still had significantly fewer binge-drinking days.
• Side effects were no more common than with placebo, and no serious side effects were linked to the treatment.

Lead author Glenn-Milo Santos said the appeal is that people can use it when they know they may be at risk of heavy drinking, rather than taking a medicine every day.

Limitations

The trial was relatively small and the researchers say larger studies are needed in broader populations. It used a standardised formulation; UCSF warns that over-the-counter kudzu supplements vary and may not give the same results. Everyone also received counselling. If you are worried about your drinking, talk to your doctor.