Loading…
We use essential cookies (authentication, your saved goals/stack) by default. With your permission we’ll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies
Head-to-head evidence comparison — which supplement is right for you?
Saccharomyces Boulardii vs Vitamin K2: Saccharomyces Boulardii has the stronger overall evidence (8.5 vs 5/10); the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Saccharomyces Boulardii wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
4 of 4 studies with measurable effects showed benefit.
Top outcomes
Verdict
Probably helps
3 of 5 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Saccharomyces Boulardii and Vitamin K2 have evidence — compare verdict strength side-by-side.
250-500mg (5-10 billion CFU) daily
With or without food, At least 2 hours away from antifungals
Capsules (lyophilized)
100-200mcg (MK-7)
With a meal containing fat
MK-7 (menaquinone-7)
During use
1-3 days
1-2 weeks
4-12 weeks
1-3 years
1-3 years
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
Meta-analysis of 19 studies with 5,036 people with H. pylori infection, adding S. boulardii to standard eradication therapy.
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.
Vitamins K2 and D3 Improve Long COVID, Fungal Translocation, and Inflammation: Randomized Controlled Trial
Nutrients (2025) · Rct · n=151
The median age was 46 years; 71% were female and 29% were non-white.
The effect of vitamin K2 supplementation on bone turnover biochemical markers in postmenopausal osteoporosis patients: a systematic review and meta-analysis
Frontiers in endocrinology (2025) · Meta analysis · n=2570
Vitamin K2 (VK2) increased osteocalcin (OC; MD 1.86, 95% CI 1.17-2.56) and bone-specific alkaline phosphatase (BAP; MD 1.49, 95% CI 0.98-2.00).
Vitamin K2 in Managing Nocturnal Leg Cramps: A Randomized Clinical Trial
JAMA internal medicine (2024) · Rct · n=199
Of the 199 enrolled individuals, 108 (54.3%) were female, and the mean (SD) age was 72.3 (5.5) years.
Both points come from a meta-analysis of 10 randomised trials adding S. boulardii to bismuth quadruple therapy (PMID 40251486), whose dose subgroups found the same gain in eradication at 500 mg a day (RR 1.10, 95% CI 1.03 to 1.17) and 1000 mg a day (RR 1.08, 95% CI 1.03 to 1.12). Effectiveness is the relative gain in eradication in percent. Total adverse effects fell with S. boulardii (RR 0.53), so the side effect values are low. The authors recommend 500 mg a day for more than 10 days. The effect is as an add-on to antibiotics only, and doses are in mg of product, not CFU.
In a 1-year randomised trial of 311 Chinese men and postmenopausal women, 90 μg of MK-7 a day slowed femoral neck bone loss in the postmenopausal women and 50 μg did not, with no effect in men (PMID 32060566). In a 3-year randomised placebo-controlled trial of 244 healthy postmenopausal women, 180 μg a day reduced the decline in bone density at the lumbar spine and femoral neck but not the total hip (PMID 23525894). In a 3-year randomised placebo-controlled trial of 142 postmenopausal women with osteopenia, 375 μg a day with calcium and vitamin D did not change bone density at any site (PMID 33030563). The curve stays flat above 90 μg because no trial compared 90 μg with a higher dose, and the 375 μg trial found no effect. The cited BMD meta-analyses do not state a dose and mostly pool menaquinone-4 trials, so they are not plotted.
AI-estimated from published studies. Interpret as directional guidance.
Saccharomyces Boulardii has a higher evidence score (8.5/10 vs 5/10) and wins in 2 of 3 categories.
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
Which supplements clash with blood thinners, thyroid meds, antibiotics & more — and what to do.
Hot flashes, bone, sleep, muscle — the basics that hold up vs the phytoestrogen hype.
Worth it if you’re deficient (and many are) — dosing, testing, D3 vs D2, and the K2 question.
When to take what, with or without food, and which supplements compete vs pair well.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.