Can herbal extract kudzu curb binge drinking?

Clinical takeaway: For patients with alcohol use disorder asking about kudzu, explain that the standardized kudzu extract studied in this trial reduced binge-drinking days when taken before anticipated heavy drinking and paired with counseling. Larger trials are needed, and results cannot be assumed to apply to other over-the-counter formulations.

Many patients with alcohol use disorder (AUD) want to cut back, yet medication treatment remains underused. An as-needed approach could appeal to people who can anticipate heavy-drinking situations and prefer intermittent treatment.

The double-blind, phase 2b A-HACK trial randomized 120 adults with AUD who binge drank at least weekly to standardized kudzu extract or placebo for 12 weeks. Participants took 2 grams at least 2.5 hours before anticipated heavy drinking. Both groups received brief weekly counseling.

In the intention-to-treat analysis, kudzu reduced binge-drinking days by 27% relative to placebo. Average weekly binge-drinking days fell from 2.15 to 1.42 with kudzu, compared with 2.15 to 2.06 with placebo.

Kudzu also reduced the likelihood of a week with any binge drinking by 21%. Three months after treatment ended, the kudzu group still reported 32% fewer binge-drinking days relative to placebo.

However, the primary analysis found no significant differences in total monthly drinks or either alcohol biomarker. A subgroup taking study medication more frequently showed stronger benefits, but that analysis was vulnerable to selection bias.

Adverse event frequency was similar between groups, with no serious events attributed to kudzu. The small, single-region sample and reliance on self-reported drinking limit generalizability.

“What’s exciting about this approach is that people can use it when they know they may be at risk of heavy drinking, rather than taking a medication every day,” lead author Glenn-Milo Santos, PhD, MPH, said in a UCSF news release.

Source: Santos G-M, et al. (2026 Nov 4) Am J Psychiatry. Targeted Use of Kudzu for Binge Drinking Among Adults With Alcohol Use Disorder: A Phase 2b Randomized Trial