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Head-to-head evidence comparison — which supplement is right for you?
Saccharomyces Boulardii wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
9 of 11 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
13 of 15 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both NAC and Saccharomyces Boulardii have evidence — compare verdict strength side-by-side.
600-1800mg daily
Away from food, Split into 2-3 doses
NAC capsules or powder
250-500mg (5-10 billion CFU) daily
With or without food, At least 2 hours away from antifungals
Capsules (lyophilized)
4-8 weeks
2-4 weeks
1-2 weeks
Immediate
During use
1-3 days
1-2 weeks
Efficacy of N-Acetylcysteine in Polycystic Ovary Syndrome: Systematic Review and Meta-Analysis
Nutrients (2025) · Meta analysis · n=2515
NAC was associated with a statistically significant increase in progesterone (SMD 0.95, 95% CI: 0.13-1.77, p = 0.02) and endometrial thickness (SMD 0.58, 95% CI: 0.10-1.06, p = 0.02) compared to the placebo and other drugs (SMD 0.71, 95% CI: 0.48-0.94, p < 0.0001).
Efficacy of N-acetylcysteine for patients with depression: An updated systematic review and meta-analysis
General hospital psychiatry (2024) · Meta analysis · n=904
Our findings indicate that adjunctive NAC can ameliorate depressive symptoms in patients with psychiatric problems, particularly bipolar disorder.
N-acetylcysteine as a treatment for substance use cravings: A meta-analysis
Addiction biology (2024) · Meta analysis · n=623
The most targeted substance in the clinical trials was alcohol (3/9; 33.3%), followed by tobacco (2/9; 22.2%) and multiple substances (2/9; 22.2%).
Efficacy and safety of Saccharomyces boulardii as an adjuvant therapy for the eradication of Helicobacter pylori: a meta-analysis
Frontiers in cellular and infection microbiology (2025) · Meta analysis · n=5036
S. boulardii supplementation in traditional eradication therapy significantly improves the H. pylori eradication rate and reduces the total adverse effects and incidence of diarrhea, bloating, constipation, and nausea.
Probiotics for treating acute infectious diarrhoea
The Cochrane database of systematic reviews (2020) · Meta analysis · n=12127
Effect size was similar in the sensitivity analysis and marked heterogeneity persisted.
The use of probiotics and prebiotics in decolonizing pathogenic bacteria from the gut; a systematic review and meta-analysis of clinical outcomes
Gut microbes (2024) · Meta analysis · n=2871
This review aims to analyze available evidence from human-controlled trials to determine the effect size of probiotic interventions in decolonizing AMR pathogenic bacteria from the gut.
Meta-analysis showed efficacy particularly in bipolar disorder patients. Effect appears as adjunctive treatment. Individual response varies significantly.
Based on multiple meta-analyses showing 1.1-1.6 day reduction in diarrhea duration. Effect size appears to plateau at standard therapeutic doses. Limited data on doses above 20 billion CFU.
AI-estimated from published studies. Interpret as directional guidance.
Saccharomyces Boulardii has a higher evidence score (8.5/10 vs 6/10) and wins in 2 of 3 categories.
For reduce inflammation, Saccharomyces Boulardii has a higher relevance score (90 vs 60).
No known interactions between NAC and Saccharomyces Boulardii have been documented in our database. However, always consult a healthcare provider before combining supplements.