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Head-to-head evidence comparison — which supplement is right for you?
L-Glutamine wins 1 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
3 of 3 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 L-Glutamine and Saccharomyces Boulardii have evidence — compare verdict strength side-by-side.
5-10g
Post-workout, Before bed, Or split throughout day
L-Glutamine powder
250-500mg (5-10 billion CFU) daily
With or without food, At least 2 hours away from antifungals
Capsules (lyophilized)
2-4 weeks
2-4 weeks
1-2 weeks
During use
1-3 days
1-2 weeks
A Phase 3 Trial of l-Glutamine in Sickle Cell Disease
The New England journal of medicine (2018) · Rct · n=230
A total of 230 patients (age range, 5 to 58 years; 53.9% female) were randomly assigned, in a 2:1 ratio, to receive l-glutamine (152 patients) or placebo (78 patients).
What Is the Role of Nutritional Supplements in Support of Total Hip Replacement and Total Knee Replacement Surgeries? A Systematic Review
Nutrients (2018) · Systematic review
Amino acid supplementation is reported to reduce muscle atrophy and accelerate return of functional mobility.
Evidence and gaps in clinical outcomes of novel pharmacologic therapies for sickle cell disease: A systematic literature review highlighting insights from clinical trials and real-world studies
Blood reviews (2025) · Systematic review · n=97
A pivotal phase III study of l-glutamine showed that patients treated with l-glutamine had a 25 % reduction in pain crises and 33 % fewer hospital days compared to placebo. l-glutamine was generally well tolerated with minimal side effects.
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.
Based on RCT showing reduced URTI incidence in combat athletes (n=21) and enhanced IgA levels. Limited sample size and specific population studied. Effect may be primarily in high-stress/training conditions.
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.
L-Glutamine has a higher evidence score (9/10 vs 9/10) and wins in 1 of 3 categories.
For reduce inflammation, Saccharomyces Boulardii has a higher relevance score (90 vs 85).
No known interactions between L-Glutamine and Saccharomyces Boulardii have been documented in our database. However, always consult a healthcare provider before combining supplements.