About Florastor
Florastor is the North American brand name for Saccharomyces boulardii CNCM I-745, a probiotic yeast strain discovered in 1923 by French microbiologist Henri Boulard, who traced its origins to a fermented tea made from lychee and mangosteen used to treat digestive illness in Indochina. The French pharmaceutical company Biocodex acquired exclusive rights to the strain in 1953, developed it into a pharmaceutical-grade product, and registered it at the Pasteur Institute in Paris in 1988. Biocodex brought the strain to the US and Canadian markets under the Florastor name in 2002.
Florastor remains the only Saccharomyces boulardii CNCM I-745 probiotic sold in North America, with the strain now studied in more than 130 clinical trials and used in over 100 countries. Because it's a yeast rather than a bacterium, it isn't affected by antibiotics, letting it be taken alongside a prescription course rather than staggered around doses, a distinction we highlighted when featuring it in our own probiotic reviews. In our reviews, its capsule and powder formats are freeze-dried and shelf-stable for up to three years without refrigeration, holding up well for both everyday stock and episodic use during illness or travel.
Brand website: florastor.com
What Florastor makes
Florastor's range runs wider than the products we review. The lines we know best from our own testing are marked with a star:
Florastor Daily Probiotic Capsules
adult 250mg Saccharomyces boulardii CNCM I-745 capsules for digestive and immune support — featured on BestRatedDocs
Florastor Kids Dual Action Probiotic Powder
tutti-frutti flavored powder sticks for children, mixes into cold food or drink — featured on BestRatedDocs
FlorastorBaby Dual Action Probiotic Powder
unflavored powder for infants and toddlers from 12 months, mixes into milk, formula, or soft food
Florastor Kids Probiotic Sachets (unflavored)
an unflavored powder format for kids as an alternative to the flavored sticks
Why we recognized Florastor
The BestRatedDocs Top Brand recognition isn't paid for and can't be applied for. We award it to the brands whose products consistently stand out in our category reviews. Florastor earned it on the strength of the products below, evaluated the same way every product on this site is: assessed against clinical criteria, verified specifications, and real-world user outcomes, and judged on merit.
Florastor products we rated highly
Florastor Daily Probiotic Supplement
Saccharomyces boulardii CNCM I-745 is a yeast, not a bacterium, so it survives co-administration with antibiotics that would kill bacterial strains. In our reviews it stood out as the only yeast-based product in the roundup, backed by more than 50 years of clinical research on antibiotic-associated diarrhea and C. difficile prevention, and it ships in freeze-dried vegetarian capsules with a three-year shelf life that needs no refrigeration.
Read the 7 Best Probiotics of 2026 guide →
Florastor Kids Dual Action Probiotic Powder
Because Saccharomyces boulardii is a yeast rather than a bacterium, antibiotics can't kill it, so it can be given at the same time as a course rather than staggered around doses. In our reviews it's approved from 12 months of age, mixes into any cold food or drink, and carries a three-year shelf life with no refrigeration needed, so a box can sit ready until the next prescription.
Read the Best Probiotics for Kids of 2026 guide →What earned Florastor the recognition
- Florastor is the only Saccharomyces boulardii CNCM I-745 probiotic sold in North America, a yeast-based strain that antibiotics don't affect, unlike bacterial probiotics.
- The S. boulardii strain has been studied in more than 130 clinical trials and used in over 100 countries, with Biocodex tracing its pharmaceutical development back to 1953.
- Florastor earned a place across two categories we cover: general digestive health probiotics and kids' probiotics, reviewed for both adult and pediatric use cases.
- Every capsule and powder format we reviewed is freeze-dried and shelf-stable for up to three years without refrigeration, useful for stockpiling ahead of antibiotic courses or travel.
- Florastor Kids Dual Action Probiotic Powder carries a 4.7-star rating in our kids' probiotics review, and the adult Daily Probiotic Supplement holds a 4.6-star rating across more than 16,000 verified Amazon reviews.