N-Acetyl Cysteine (NAC) for Obsessive Thought Reduction

NAC is the most-studied supplement adjunct here, but works better for compulsive behaviours than for pure obsessional thinking.

Overview

NAC is the most-studied supplement adjunct here, but works better for compulsive behaviours than for pure obsessional thinking.

Verdict

Mixed evidence

How It Works

NAC modulates glutamate release in the corticostriatal circuits implicated in OCD, potentially reducing the drive behind repetitive behaviour.

Dosing & Protocol

Typical dose

Recommended dose: 1200-2400mg/day in divided doses
Expected timeframe: 10-12 weeks

Protocol

form: N-acetylcysteine capsules
duration: 12-24 weeks - trials that showed benefit ran at least 12 weeks
co factor: Take away from food, in divided doses. Evidence is mixed. NAC modulates glutamate through the cystine-glutamate antiporter in the nucleus accumbens, and glutamatergic dysregulation in cortico-striatal circuits is a leading model of obsessive-compulsive and body-focused repetitive behaviours - a coherent rationale. A randomised trial in trichotillomania at 1,200-2,400 mg/day showed clear benefit, and some trials in skin picking are positive. In OCD itself the results are inconsistent: several adjunctive trials at 2,400-3,000 mg/day report modest Y-BOCS reductions while others, including well-conducted ones, show no separation from placebo, and meta-analyses conclude the effect is small and uncertain.
titration: Increase over 1-2 weeks to 1,200 mg twice daily (2,400 mg/day), up to 3,000 mg/day as tolerated. Gastrointestinal intolerance is the usual limiting factor
starting dose: 600 mg twice daily on an empty stomach, as an adjunct to established treatment

Evidence

What the studies say

Trials at 2400-3000mg/day over 10-12 weeks show benefit for trichotillomania and skin picking, with more equivocal results in classic OCD. Several OCD trials were null. It is an adjunct to ERP and SSRIs, not a substitute.

N-acetylcysteine augmentation in treatment-resistant obsessive-compulsive disorder: a randomized double-blind placebo-controlled trial

Score: 8/10

2017

rct

n=40

Costa DLC, Diniz JB, Requena G +5 more

NAC did not outperform placebo on the primary Yale-Brown obsessive-compulsive scale outcome

View source

N-acetylcysteine in obsessive-compulsive and related disorders: a systematic review and meta-analysis

Score: 7/10

2015

systematic_review

Oliver G, Dean O, Camfield D +4 more

NAC augmentation reduced obsessive-compulsive symptom severity in several trials

View source

Safety

Caveats

Nausea is common. Never delay ERP therapy in favour of a supplement trial.

Less likely to help if

People with classic OCD, where trials are inconsistent, and anyone not also receiving ERP or an SSRI.

Medical Disclaimer

The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.