NAC (N-Acetyl Cysteine) for OCD
Acetylated form of the amino acid cysteine and the rate-limiting precursor for glutathione, the body's principal antioxidant; used clinically as the antidote for paracetamol overdose and studied for respiratory and mental health.
NAC (N-Acetyl Cysteine) for OCD
4 of 7 results reported a benefit, from 4 published studies.
4 studies, including a review of trials · the chart counts everything measured
- 4 reported a benefit
- 3 no clear benefit
Colour keyReported a benefitNo clear benefitUnclearPossible harmAmber is for highlights, such as where the most research is. It never means a result was good.
- OCD symptomsNo clear difference0.53 higher, unit not reported1 randomised trial2 of 4 results reported a benefit2022 study ↗
- Obsession and compulsion sub-scoresNo clear benefit foundmeasurement not reportedN-acetylcysteine (NAC) augmentation with SSRIs did not significantly improve Obsession and compulsion Y-BOCS scores compared with placebo; the difference versus placebo was not statistically established in 195.1 review of trials2024 study ↗
- Obsession symptomsReported a benefitsee exact figuresN-acetylcysteine (NAC) augmentation with fluvoxamine improved Y-BOCS obsession subscale compared with placebo in 44 (10-week).1 randomised trial2016 study ↗
Also measured in these studies (1)
These were measured alongside, but they are not what this condition is about.
- Anxiety symptomsReported a benefitsee exact figuresN-acetylcysteine (NAC) improved anxiety symptoms compared with placebo in Forty subjects (16-week).1 randomised trial2017 study ↗
Side effects: measured in 2 results. 1 result reported more side effects than the comparison group.
These are the figures the studies reported, not a prediction for any one person. Where several studies measured the same thing in the same unit, we show a simple average and say so. Every result is listed below.
See every resultThe connection
Obsessive-compulsive disorder. Intrusive thoughts and repetitive behaviours that are difficult to control.
Also known as: NAC, N-Acetyl-L-Cysteine
NAC (N-Acetyl Cysteine) × OCD: at a glance
Every published result for this pair, extracted and audited.
These charts count reported findings from published studies, grouped by reported benefit and study design. Study design is not a certainty grade.
NAC (N-Acetyl Cysteine) / OCD: reported findings; one study may contribute several findings.
What the evidence shows
What this means: Counts describe research quantity, not treatment effectiveness or certainty.
| Category | Findings (count) |
|---|---|
| No benefit | 4 |
| Benefit | 4 |
| Harm / risk | 1 |
Study designs behind these findings
What this means: Counts describe research quantity, not treatment effectiveness or certainty.
| Category | Findings (count) |
|---|---|
| Systematic review | 3 |
| Randomised trial | 6 |
- Studies
- 4
| Study | Outcome | Reported result | Uncertainty (as reported) | Study duration |
|---|---|---|---|---|
| The safety and efficacy of N-acetylcysteine as an augmentation in the treatment of obsessive-compulsive disorder in adults: a systematic review and meta-analysis of randomized clinical trials. (PMID 39376972) | Adverse events | Not reported | Not reported | Not reported |
| The safety and efficacy of N-acetylcysteine as an augmentation in the treatment of obsessive-compulsive disorder in adults: a systematic review and meta-analysis of randomized clinical trials. (PMID 39376972) | Obsession and compulsion Y-BOCS scores | Not reported | Not reported | Not reported |
| The safety and efficacy of N-acetylcysteine as an augmentation in the treatment of obsessive-compulsive disorder in adults: a systematic review and meta-analysis of randomized clinical trials. (PMID 39376972) | Total Y-BOCS score | p-Value = 0.05 | Not reported | five to eight weeks |
| N-acetyl cysteine (NAC) augmentation in the treatment of obsessive-compulsive disorder: A phase III, 20-week, double-blind, randomized, placebo-controlled trial. (PMID 35304155) | Yale-Brown Obsessive-Compulsive Scale (OCD symptoms) | mean difference at week 20 = 0.53 | p = 0.70 | 20-week |
| Randomized, Double-Blind, Placebo-Controlled Trial of N-Acetylcysteine Augmentation for Treatment-Resistant Obsessive-Compulsive Disorder. (PMID 28617566) | abdominal pain | 9 [60.0] | P < .01 | 16-week |
| Randomized, Double-Blind, Placebo-Controlled Trial of N-Acetylcysteine Augmentation for Treatment-Resistant Obsessive-Compulsive Disorder. (PMID 28617566) | anxiety symptoms | Not reported | P = .02 | 16-week |
| Randomized, Double-Blind, Placebo-Controlled Trial of N-Acetylcysteine Augmentation for Treatment-Resistant Obsessive-Compulsive Disorder. (PMID 28617566) | Y-BOCS scores | 4.3 points | P = .92 | 16-week |
| N-acetylcysteine augmentation therapy for moderate-to-severe obsessive-compulsive disorder: randomized, double-blind, placebo-controlled trial. (PMID 26931055) | Y-BOCS obsession subscale | F = 5·44 | P = 0·011 | 10-week |
| N-acetylcysteine augmentation therapy for moderate-to-severe obsessive-compulsive disorder: randomized, double-blind, placebo-controlled trial. (PMID 26931055) | Y-BOCS total score | F = 5·14 | P = 0·012 | 10-week |
Study results, as reported by the publications
Every measured outcome, one row per finding - numbers exactly as reported. Units are preserved where supplied; missing units are not inferred.
| Study and type | Reported sample and duration | Outcome measured | Reported result | What studies found |
|---|---|---|---|---|
| PMID 39376972 2024 Systematic review | Sample (as reported): 195Duration: Not reported | Adverse events | Not reported | No benefit |
| PMID 39376972 2024 Systematic review | Sample (as reported): 195Duration: Not reported | Obsession and compulsion Y-BOCS scores | Not reported | No benefit |
| PMID 39376972 2024 Systematic review | Sample (as reported): 195Duration: five to eight weeks | Total Y-BOCS score | p-Value = 0.05 | Benefit |
| PMID 35304155 2022 Randomised trial | Sample (as reported): 98Duration: 20-week | Yale-Brown Obsessive-Compulsive Scale (OCD symptoms) | mean difference at week 20 = 0.53 (p = 0.70) | No benefit |
| PMID 28617566 2017 Randomised trial | Sample (as reported): Forty subjectsDuration: 16-week | abdominal pain | 9 [60.0] (P < .01) | Harm / risk |
| PMID 28617566 2017 Randomised trial | Sample (as reported): Forty subjectsDuration: 16-week | anxiety symptoms | Not reported (P = .02) | Benefit |
| PMID 28617566 2017 Randomised trial | Sample (as reported): Forty subjectsDuration: 16-week | Y-BOCS scores | 4.3 points (P = .92) | No benefit |
| PMID 26931055 2016 Randomised trial | Sample (as reported): 44Duration: 10-week | Y-BOCS obsession subscale | F = 5·44 (P = 0·011) | Benefit |
| PMID 26931055 2016 Randomised trial | Sample (as reported): 44Duration: 10-week | Y-BOCS total score | F = 5·14 (P = 0·012) | Benefit |
NAC (N-Acetyl Cysteine) × OCD: the evidence base
Hand-selected PubMed studies, linked to the originals.
Ordered by strength of evidence, then result direction.
01Comparison of adjuvant and neoadjuvant therapies for muscle invasive bladder cancer: A network meta-analysisPetrelli F, et al. · Urologic oncology · 2026PMID 40935764 ↗02The safety and efficacy of N-acetylcysteine as an augmentation in the treatment of obsessive-compulsive disorder in adults: a systematic review and meta-analysis of randomized clinical trialsEghdami S, et al. · Frontiers in psychiatry · 2024PMID 39376972 ↗03The impact of N-acetylcysteine on lactate, biomarkers of oxidative stress, immune response, and muscle damage: A systematic review and meta-analysisSadowski M, et al. · Journal of cellular and molecular medicine · 2024PMID 39632267 ↗04Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders guidelines for the treatment of adult obsessive-compulsive disorder. Part I: pharmacological treatmentde Oliveira MVS, et al. · Revista brasileira de psiquiatria (Sao Paulo, Brazil : 1999) · 2023PMID 36749887 ↗05Effect of neoadjuvant chemotherapy on tumor immune infiltration in breast cancer patients: Systematic review and meta-analysisLlano-León M, et al. · PloS one · 2023PMID 37104271 ↗06Clinical Recommendations for Augmentation Agents in Obsessive-Compulsive Disorder Partially Responsive to Serotonin Reuptake InhibitorsGautam M · Journal of clinical psychopharmacology · 2023PMID 37335203 ↗Community experiences
Contributors volunteered; this does not establish treatment effectiveness or population incidence.
Reported changes
No publishable community breakdown is available. This does not establish that no reports exist.