Saccharomyces boulardii Dosage: How Much and When to Take
Overview
Saccharomyces boulardii is typically dosed at 250-500 mg (approximately 5-10 billion CFU) once or twice daily. Unlike bacterial probiotics, it can be taken at the same time as antibiotics because it’s naturally antibiotic-resistant. The specific dose depends on the condition being treated.
Standard Dosing
Typical adult doses:
- Prevention: 250-500 mg once or twice daily
- Treatment: 250-500 mg twice daily
- Most products contain approximately 5 billion CFU per 250 mg
Common regimens:
- Florastor: 250 mg twice daily (standard)
- Some products: 500 mg once daily
- Higher doses used in some clinical studies
Dosing by Condition
Antibiotic-associated diarrhea prevention:
- 250 mg twice daily OR 500 mg once daily
- Start when antibiotics begin
- Continue for 1-2 weeks after antibiotics end
- Can take at same time as antibiotic doses
Traveler’s diarrhea prevention:
- 250 mg twice daily
- Start a few days before travel
- Continue throughout trip
- Continue for several days after returning
Acute infectious diarrhea:
- 250-500 mg twice daily
- Continue until symptoms resolve
- Plus additional 1-2 days
- Stay hydrated alongside treatment
C. difficile prevention/recurrence:
- 250-500 mg twice daily
- Used alongside prescribed antibiotics for C. diff
- Continue 4 weeks after antibiotic completion
- Medical supervision recommended
H. pylori treatment support:
- 250 mg twice daily
- Taken with standard triple or quadruple therapy
- May reduce antibiotic side effects
- Continue through antibiotic course
How to Take
Timing:
- Can take with or without food
- Can take at same time as antibiotics (major advantage)
- Consistency in timing helps establish routine
- Once or twice daily depending on product/indication
With antibiotics — no separation needed:
- S. boulardii is a yeast, not bacteria
- Antibiotics don’t affect it
- Can swallow together with antibiotic dose
- Simplifies medication schedule
Administration:
- Swallow capsules whole with water
- Powder can be mixed with cool or room temperature liquid
- Don’t use hot beverages (kills the yeast)
- Chewables should be chewed thoroughly
Age-Specific Dosing
Adults:
- Standard: 250-500 mg once or twice daily
- Up to 1000 mg daily in some studies
- Follow product recommendations
Children (age 3+):
- Florastor Kids: 250 mg once or twice daily
- Pediatric products available
- Powder or chewable forms easier
Infants and toddlers:
- Consult pediatrician
- Lower doses may be used
- Mix powder with formula, breast milk, or food
- Usually 250 mg daily or less
Elderly:
- No dose adjustment needed
- Same as adult dosing
- May benefit particularly during antibiotic use
Duration of Use
Short-term use:
- During antibiotic courses
- Traveler’s diarrhea prevention (during trip)
- Acute diarrhea episodes
- Usually 1-4 weeks
Extended use:
- C. difficile recurrence prevention: 4+ weeks after antibiotics
- Some chronic digestive conditions
- Long-term use appears safe
- Discuss with healthcare provider
When to stop:
- After completing antibiotic course + 1-2 weeks
- When traveling is complete
- When acute symptoms resolve
- Per healthcare provider guidance
Timing Relative to Antibiotics
Key advantage of S. boulardii:
| Probiotic Type | Timing with Antibiotics |
|---|---|
| Bacterial (Lactobacillus, etc.) | Must take 2-3 hours apart |
| Saccharomyces boulardii | Can take together |
This makes S. boulardii more convenient during antibiotic treatment.
What If You Miss a Dose?
If you forget:
- Take when you remember
- If almost time for next dose, skip the missed one
- Don’t double up on doses
- Return to regular schedule
Occasional misses:
- Generally not problematic
- Consistent use is better
- Return to routine as soon as possible
Product Selection
What to look for:
- Specific strain name (S. boulardii CNCM I-745 or lyo)
- CFU count guaranteed at expiration
- Reputable manufacturer
- Appropriate form for your needs
Popular products:
- Florastor (CNCM I-745 strain — most studied)
- Generic S. boulardii products
- Combination products with other probiotics
Storage
Most products:
- Shelf-stable at room temperature
- Store in cool, dry place
- Keep away from heat and moisture
- Check expiration dates
Unlike bacterial probiotics:
- Refrigeration usually not required
- More stable at room temperature
- Good for travel
Combining with Other Probiotics
Taking with bacterial probiotics:
- Generally safe to combine
- Some products contain both
- Different mechanisms may complement
- Not necessary but not harmful
Considerations:
- May be redundant for same indication
- Each has specific evidence base
- S. boulardii preferred during antibiotics (resistance advantage)
- Discuss with healthcare provider if uncertain
Saccharomyces boulardii supplements are widely available over the counter — view on Amazon.
Sources
Doses shown reflect commonly cited ranges in probiotic research. Optimal dosing varies by strain and condition; follow your specific product’s label and your healthcare provider’s guidance.
- National Institutes of Health Office of Dietary Supplements. Probiotics. Health Professional Fact Sheet. https://ods.od.nih.gov/factsheets/Probiotics-HealthProfessional/. Accessed March 2026.
- National Institutes of Health Office of Dietary Supplements. Probiotics. Consumer Fact Sheet. https://ods.od.nih.gov/factsheets/Probiotics-Consumer/. Accessed March 2026.
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