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.