Drinking multiple alcoholic drinks on a single occasion (binge drinking), has many negative health risks but interventions to address this behavior remain limited. This double-blind, placebo-controlled randomized clinical trial will test whether kudzu, an herbal supplement, can reduce heavy alcohol use and alcohol-associated sexual behaviors among sexually-active, binge-drinking individuals at high risk for HIV infection.

This study, entitled "The Harness Study" is a double-blind, placebo-controlled, two-arm trial in which 120 binge drinkers with AUD will be randomly assigned to receive 12 weeks of kudzu or placebo, to be taken on an as-needed basis with 1- and 3-month post-treatment follow-up visits. This efficacy study will enroll sexually active, binge drinkers with AUD because they are the most likely population to benefit from this intervention by limiting harms associated with heavy alcohol use and decreasing alcohol-related sexual risk behaviors. A study clinician will perform the Structured Clinical Interview for the DSM-V (SCID) to screen for AUD and determine eligibility. Upon enrollment, 120 participants will be randomized 1:1 to kudzu extract (2 grams) or placebo for targeted administration. Participants will be seen weekly for behavioral surveys, urinalyses, study drug dispensing, and alcohol use counseling. Safety laboratory assessment, vital signs, and the audio computer assisted survey instrument (ACASI) will be completed monthly. Efficacy, tolerability, and acceptability (Specific Aims 1-4) will be assessed upon trial completion as measured by number of binge drinking occasions and numbers of drinks on drinking days via timeline follow-back at weekly visits; number of EtG-positive urine samples; sexual risk behavior data through monthly surveys via ACASI; frequency of adverse events; and cumulative medication adherence data at week 12. Durability of intervention effects will be evaluated at 1- and 3-month post-treatment visits.

Inclusion Criteria:

1. Self-reported anal or vaginal sex in the prior three months while under the influence of alcohol, or reported missing ART or PrEP due to alcohol use in the prior 3 months;
2. at least one binge-drinking (five or more drinks on a single occasion for men; four or more drinks for women) session per week in the prior three months;
3. having an AUD by DSM-5 SCID criteria (includes hazardous and harmful use);
4. interested in reducing binge alcohol consumption;
5. HIV negative by rapid antibody test and HIV pooled RNA test; or HIV positive with a medical record documentation of HIV infection.* For HIV-positive individuals, having a CD4 cell count >100 cells/mm3 and having suppressed HIV viral load with < 50 copies/mm3; *
6. no current acute illnesses requiring prolonged medical care;
7. no chronic illnesses that are likely to progress clinically during trial participation;
8. able and willing to provide informed consent and adhere to visit schedule;
9. age 18-70 years;
10. baseline CBC, total protein, albumin, glucose, alkaline phosphatase, creatinine, BUN, and electrolytes without clinically significant abnormalities as determined by study clinician in conjunction with symptoms, physical exam, and medical history;

(*Note: Participants newly diagnosed with HIV at screening are eligible for the study but we will postpone their enrollment until they are virally suppressed with HIV viral load < 50 copies/mm .)

Exclusion Criteria:

1. Any psychiatric (e.g., depression with suicidal ideation) or medical condition that would preclude safe participation in the study;
2. known allergy/previous adverse reaction to kudzu;
3. moderate/severe liver disease (AST, ALT > 5 times upper limit of normal);
4. impaired renal function (creatinine clearance < 50 ml/min);
5. currently participating in another intervention research study with potential overlap;
6. current severe substance-use disorder (exclusive of nicotine, cannabis or alcohol) as determined by DSM-V SCID criteria;
7. pregnant women;
8. HIV positive individuals who are not virally suppressed;
9. any condition that, in the principal investigator and/or study clinician's judgment interferes with safe study participation or adherence to study procedures
10. not willing to learn how to send EMA surveys.

(*Note: Eligible participants who have a partner currently in the study will be enrolled and randomized after their partner has completed their in-treatment follow-up, to reduce the concerns of contamination between treatment conditions. Additionally, we will exclude individuals with impaired renal function as a general precaution. Pharmacokinetic data on kudzu is limited. Puerarin is present in the urine of rats for 4-72 hours after oral administration, thus there is renal elimination of the active compound, as well as it's metabolite, equol. For this reason, we prefer to be cautious by limiting enrollment to those with reasonable renal function. We selected eGFR < 50mL/min as that is the level at which most products with renal clearance begin to demonstrate risks of increased toxicity.)