This study is a double-blind randomised controlled trial to compare the efficacy of 12 weeks of N-acetylcysteine (NAC, 2400mg/day) versus placebo on alcohol consumption.

Double-blind means that neither the participant nor the study staff will know in advance the participant treatment group. Participants will be asked to take 4 capsules daily – two in the morning, and two in the evening for a period of 12 weeks.

Participants can expect:

  • Brief medical consultation at baseline and week 12
  • 6 visits during the 12 week treatment period.
  • 3 blood tests performed at baseline, week 6 and week 12.
  • Complete a wide array of questionnaires involving alcohol usage effects to both their physical and mental health. Baseline visit is about 1.5 hours and following visits less than an hour

There are no costs involved, free parking is available at the medical centre.

Eligibility criteria

Inclusion Criteria:

  •  A desire to reduce or stop drinking
  • Consumed at on average more than 2 drinks per day (or 21 drinks over average week) or 2 occasions per week where drinking ≥5 standard drinks/day for men; ≥4 for women in the month prior to screening.
  • Adequate cognition and English language skills to give valid consent and complete research interviews
  • Age 18-70
  • Stable housing

Exclusion Criteria:

  • Medically or psychiatrically unstable condition
  • Any substance dependence other than nicotine
  • Concurrent use of selenium, vitamin D or other antioxidants
  • Any alcohol pharmacotherapy within the past month.
  • Pregnancy or lactation

Participant benefits

Participants will be reimbursed $30 shopping vouchers for non-alcoholic goods at end of treatment visit (week 12)

Register your interest

To register your interest email: or phone: 07 3176 5191. 

This study has been approved by The University of Queensland Human Research Ethics Committee [Approval No.2022/HE000558].