Best Saccharomyces Boulardii Supplements (2026)

Saccharomyces boulardii is a unique probiotic yeast that stands apart from bacterial probiotics in several important ways. It naturally survives stomach acid, doesn’t require refrigeration, and can’t be killed by antibiotics — making it the go-to probiotic during antibiotic treatment, travel, or acute digestive distress. Decades of clinical research support its use for preventing and managing diarrhea, restoring gut flora balance, and supporting immune function.

Quick Comparison

Product	CFU Count	Form	Best For	Rating
Jarrow Formulas S. Boulardii + MOS	5 Billion CFU	Capsules	Best Overall	9.5/10
NOW Foods Saccharomyces Boulardii	5 Billion CFU	Capsules	Best Value	9.3/10
Florastor Daily Probiotic	250 mg (CNCM I-745)	Capsules	Best Clinically Studied	9.3/10
Pure Encapsulations S. Boulardii	5 Billion CFU	Capsules	Best Hypoallergenic	9.2/10
Klaire Labs S. Boulardii Powder	9–45 Billion CFU per scoop	Powder	Best Powder Form	9.1/10
BARE & BETTER S. Boulardii	10 Billion CFU	Capsules	Best High Potency	9.0/10
Nutricost S. Boulardii + MOS	5 Billion CFU	Capsules	Best Budget Pick	8.9/10

1. Jarrow Formulas Saccharomyces Boulardii + MOS – Best Overall

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Jarrow Formulas combines a clinically studied S. boulardii strain with MOS prebiotic in delayed-release capsules for maximum gut delivery.

Each capsule delivers 5 billion CFU of Saccharomyces boulardii plus mannanoligosaccharides (MOS) — a prebiotic that feeds beneficial bacteria in the gut. The delayed-release capsule technology ensures the probiotic yeast reaches the intestinal tract intact. The 90-capsule bottle provides a full three-month supply. An innovator in consumer probiotics since 1986, Jarrow Formulas evaluates ingredient purity through cGMP compliance. Vegan, gluten-free, and free from all major allergens.

• Pros:
• Prebiotic MOS included for synergistic gut support
• Delayed-release capsules maximize intestinal delivery
• Free from all 9 major allergens — suitable for sensitive users

• Cons:
• Higher price than single-ingredient competitors
• Only available in capsule form

Best for: Anyone seeking a comprehensive S. boulardii formula with built-in prebiotic support and delayed-release technology.

2. NOW Foods Saccharomyces Boulardii – Best Value

NOW Foods delivers a solid 5 billion CFU per serving with organic inulin (FOS) prebiotic at an excellent price point.

Each two-capsule serving provides 5 billion CFU of S. boulardii (CNCM I-3799 strain) plus organic inulin (fructooligosaccharides) as a prebiotic. The 120-capsule bottle provides a 60-day supply. Room temperature stable — no refrigeration needed, though refrigeration can help preserve freshness. Manufactured in a GMP-certified facility and third-party tested. Vegetarian capsules free from major allergens.

• Pros:
• Includes organic inulin FOS prebiotic
• Clinically studied CNCM I-3799 strain
• Excellent price per serving with 120-capsule count

• Cons:
• Requires two capsules per serving to reach 5 billion CFU
• 10 billion CFU option (larger size) may be more economical for heavy users

Best for: Value shoppers who want a reliable S. boulardii with prebiotic support from a trusted mainstream brand.

3. Florastor Daily Probiotic – Best Clinically Studied

Florastor is the world’s most researched probiotic yeast brand, using the exclusive CNCM I-745 strain studied in over 100 clinical trials.

Each capsule contains 250 mg of Saccharomyces boulardii lyo CNCM I-745 — a proprietary strain that has been the subject of the most S. boulardii research worldwide. Florastor’s dual-action mechanism helps flush out harmful bacteria while boosting beneficial flora. The 100-capsule bottle provides a 50 to 100-day supply depending on dosing. Shelf stable with no refrigeration required. Can be taken alongside antibiotics without losing effectiveness.

• Pros:
• Most clinically studied S. boulardii strain available (CNCM I-745)
• Over 100 clinical trials supporting efficacy
• Dual-action: removes bad bacteria while supporting good bacteria

• Cons:
• Premium price for the branded strain
• Contains lactose monohydrate — not suitable for strict dairy-free diets

Best for: Those who want the most clinically validated S. boulardii strain with the deepest body of research behind it.

4. Pure Encapsulations Saccharomyces Boulardii – Best Hypoallergenic

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Pure Encapsulations delivers a clean, hypoallergenic S. boulardii formula trusted by functional medicine practitioners for sensitive patients.

Each capsule provides a clinically relevant dose of S. boulardii to support intestinal flora balance. Pure Encapsulations eliminates all common allergens, artificial ingredients, and GMOs from its formulations. The 60-capsule bottle provides a one to two month supply. Guided by nutritional experts and manufactured under strict quality standards, this is the preferred choice in clinical and integrative medicine settings.

• Pros:
• Free from all major allergens and unnecessary additives
• Practitioner-grade quality trusted in clinical settings
• Ultra-clean formula ideal for autoimmune and sensitive populations

• Cons:
• Higher price point than consumer-grade alternatives
• Smaller bottle size requires more frequent purchases

Best for: Individuals with multiple food sensitivities or autoimmune conditions who need an ultra-clean S. boulardii supplement.

5. Klaire Labs S. Boulardii Powder – Best Powder Form

Klaire Labs offers a pure S. boulardii powder with a dual scoop system for flexible, customizable dosing — ideal for titration protocols and children.

This single-ingredient powder provides 9 billion CFU per small scoop and 45 billion CFU per large scoop, allowing precise dose adjustments. The powder can be mixed into water, juice, or food, making it suitable for children, adults with swallowing difficulties, and high-potency titration protocols. Hypoallergenic and free from all common allergens including dairy, gluten, and soy. Freeze-dried for maximum potency. Trusted by healthcare practitioners since 1969.

• Pros:
• Flexible dosing from 9 to 45 billion CFU per serving
• Powder form ideal for children and those who can’t swallow capsules
• Hypoallergenic with zero common allergens

• Cons:
• Requires measuring — less convenient than capsules
• Higher cost than capsule-based alternatives

Best for: Parents dosing children, practitioners running titration protocols, or anyone who prefers powder over capsules.

6. BARE & BETTER Saccharomyces Boulardii – Best High Potency

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BARE & BETTER delivers 10 billion CFU per serving in a 200-count value pack — the highest capsule count for a high-potency S. boulardii.

Each capsule provides 250 mg of S. boulardii at 10 billion CFU per serving. The 200-count bottle provides over three months of daily use, eliminating the hassle of frequent reorders. No refrigeration needed — the yeast-based probiotic is naturally temperature stable. Gluten-free and lactose-free. Backed by a 100% satisfaction guarantee.

• Pros:
• 200-count bottle at 10 billion CFU — outstanding value and potency
• No refrigeration required for easy storage and travel
• Money-back satisfaction guarantee

• Cons:
• Less established brand than Jarrow or Florastor
• High CFU count may not be necessary for maintenance dosing

Best for: Budget buyers who want high potency and a large bottle count without premium pricing.

7. Nutricost Saccharomyces Boulardii + MOS – Best Budget Pick

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Nutricost pairs S. boulardii with 200 mg of MOS prebiotic per serving at one of the lowest costs on the market.

Each capsule delivers over 5 billion CFU of S. boulardii combined with mannanoligosaccharides (MOS) — a prebiotic that enhances the probiotic’s gut-colonizing effectiveness. The 120-capsule bottle provides a four-month supply at one capsule daily. Manufactured in a GMP-compliant, FDA-registered facility. Vegetarian, non-GMO, and gluten-free.

• Pros:
• One of the most affordable S. boulardii + MOS combos available
• 120-capsule bottle provides excellent long-term value
• One-capsule serving for convenience

• Cons:
• Less clinical research backing the specific strain used
• Newer brand with less established reputation in probiotics

Best for: Cost-conscious buyers who want prebiotic MOS support alongside S. boulardii without breaking the budget.

How to Choose the Best Saccharomyces Boulardii Supplement

CFU count matters, but more isn’t always better. For general gut maintenance, 5 billion CFU daily is the standard dose used in most clinical trials. Higher doses of 10–20 billion CFU may be appropriate during acute digestive distress, antibiotic use, or travel. Look for products that guarantee CFU counts through the expiration date, not just at the time of manufacturing.

Strain identification is important. The most clinically studied strains include CNCM I-745 (used by Florastor) and CNCM I-3799. Products that list specific strain designations provide more confidence in their clinical relevance. Some products also include prebiotic ingredients like MOS or FOS that feed beneficial gut bacteria and enhance S. boulardii’s effectiveness — these combination formulas can offer added value for digestive health support.

One of S. boulardii’s greatest advantages is temperature stability. Unlike most bacterial probiotics, it doesn’t require refrigeration. This makes it ideal for travel and situations where cold storage isn’t available. However, storing in a cool, dry place will extend shelf life. All forms — capsules, tablets, and powders — are effective, so choose based on personal preference and ease of dosing.

For those taking antibiotics, S. boulardii is uniquely suited because antibiotics cannot kill yeast-based probiotics. It can be taken simultaneously with antibiotic medications rather than needing to be separated by hours. If you’re dealing with broader gut issues like IBS or leaky gut, consider pairing S. boulardii with a multi-strain bacterial probiotic from our probiotics for IBS guide or an L-glutamine supplement for gut lining repair.

Frequently Asked Questions

What is Saccharomyces boulardii and what does it do?

Saccharomyces boulardii is a beneficial probiotic yeast — not a bacteria — that supports digestive health by maintaining intestinal flora balance, preventing harmful bacterial colonization, and supporting immune function. It naturally survives stomach acid and is particularly effective during antibiotic use, travel, and acute digestive distress because antibiotics don’t destroy it.

How much Saccharomyces boulardii should I take daily?

The standard dose is 250–500 mg (approximately 5–10 billion CFU) per day for general maintenance. During active digestive issues, antibiotic treatment, or travel, doses up to 1,000 mg (20 billion CFU) daily have been used in clinical studies. Follow manufacturer recommendations and consult a healthcare provider for therapeutic dosing.

When is the best time to take Saccharomyces boulardii?

S. boulardii can be taken with or without food — it survives stomach acid regardless. For consistency, taking it with a meal helps establish a routine. When using alongside antibiotics, it can be taken at the same time since antibiotics don’t affect yeast-based probiotics. Some practitioners recommend taking it 30 minutes before meals for optimal colonization.

Are there any side effects of Saccharomyces boulardii?

S. boulardii is generally very well tolerated. Some users experience mild gas or bloating during the first few days, which typically resolves quickly. It should be avoided by individuals who are severely immunocompromised or have central venous catheters, as fungemia (yeast in the bloodstream) has been reported in rare cases in these populations.

Can I take Saccharomyces boulardii with antibiotics?

Yes — this is one of S. boulardii’s key advantages. Because it’s a yeast rather than a bacterium, antibiotics cannot kill it. Clinical studies show that taking S. boulardii during antibiotic treatment significantly reduces the risk of antibiotic-associated diarrhea. It can be taken at the same time as antibiotics without separation.

How long does it take for Saccharomyces boulardii to work?

For acute diarrhea, many users notice improvement within 24–72 hours. For antibiotic-associated symptoms, benefits typically appear within three to five days. For general gut flora restoration, two to four weeks of consistent use is recommended. S. boulardii is a transient yeast, meaning it doesn’t permanently colonize the gut — ongoing supplementation is needed for sustained benefits.

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