University of Melbourne Research

N-acetylcysteine (NAC) in the treatment of Obsessive-compulsive disorder (OCD)


*Please note, recruitment for this trial is now closed. Results can be expected late 2021/early 2022*

The University of Melbourne is currently conducting a 24-week (6 month) clinical trial investigating the effects of an amino acid supplement called N-acetylcysteine (NAC) in the treatment of Obsessive-Compulsive Disorder (OCD).

NAC is a particular amino acid which has been researched for various mental health disorders including depression, bipolar disorder, schizophrenia, addiction (nicotine, marijuana, gambling) as well as OCD. NAC has anti-inflammatory and antioxidant activity, and influences various neurochemicals in the brain including glutamate. Previous research studies indicate that these properties of NAC may be effective for OCD, however, more research studies are required to determine this.

If you are eligible to participate in the study, you will be randomly allocated into the NAC group OR a placebo group (dummy capsules). You will be given capsules (NAC or placebo) to take morning and night for the 6-month study period and these capsules will be taken in addition to your current medication. If willing, we also ask that you complete a blood test at the start of the study.

Each month you will be required to attend study visits (7 visits in total) at The Melbourne Clinic in Richmond. You will meet with one of the researchers for approximately 60 minutes (the initial session may take up 90-120 mins) and complete questionnaires regarding your OCD symptoms, mood, anxiety and quality of life. 

You may be eligible to participate if you:

  • Are between the age of 18-70
  • Have been diagnosed with Obsessive-Compulsive Disorder (OCD)
  • Are currently taking medication for your OCD but still experience symptoms

The study capsules and blood test involved in the study are free of charge. You will receive Coles Myer gift vouchers throughout the 6-month study period totaling $140 as well as 3 containers of complementary NAC at the end of your participation in the study.

For further information, please contact our study staff on (03) 9487 4659 or This email address is being protected from spambots. You need JavaScript enabled to view it.