Interactions on record — worth a quick check against your medications. Based on 1 of 2 ingredients. Check your meds →
Dietary supplement

Florastor Saccharomyces Boulardii Lyo Ingredients & Drug Interactions

by Biocodex

Florastor Saccharomyces Boulardii Lyo label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Minor
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Florastor Saccharomyces Boulardii Lyo against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Minor

Florastor Saccharomyces Boulardii Lyo is a dietary supplement by Biocodex with 2 active ingredients. Its ingredients are commonly taken for acute diarrhea, antibiotic-associated diarrhea, traveler's diarrhea.Based on those ingredients, 40 medications have a known interaction with it, the most serious rated minor. The ingredients most likely to interact are Saccharomyces boulardii lyo. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Florastor Saccharomyces Boulardii Lyo by Biocodex

Ask about any prescription or over-the-counter medication and we check it for interactions with Florastor Saccharomyces Boulardii Lyo by Biocodex — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Florastor Saccharomyces Boulardii Lyo by Biocodex

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 30, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Florastor contains 2 active ingredients: Saccharomyces boulardii lyo (the probiotic yeast at the core of the product) and lactose. The capsule itself is made from inactive ingredients—magnesium stearate, hydroxypropyl-methylcellulose, and titanium dioxide—which are fillers and binders that have no therapeutic effect.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: maintains intestinal flora balance and intestinal health.
  • We looked for evidence on: Antibiotic-associated diarrhea, Travelers' diarrhea, Clostridioides difficile infection, Rotaviral diarrhea, Irritable bowel syndrome (IBS), Crohn disease — and 3 related terms.
  • The strongest evidence on file: Saccharomyces Boulardii is rated "Possibly Effective" for Antibiotic-associated diarrhea (Natural Medicines).
  • Also on file: Saccharomyces Boulardii is rated "Possibly Effective" for Rotaviral diarrhea, Travelers' diarrhea, Clostridioides difficile infection.
  • Also on file: Saccharomyces Boulardii is rated "Insufficient Reliable Evidence To Rate" for Crohn disease, Ulcerative colitis, Irritable bowel syndrome (IBS).

Saccharomyces boulardii is rated possibly effective for six gastrointestinal conditions: rotaviral diarrhea, traveler's diarrhea, antibiotic-associated diarrhea, necrotizing enterocolitis (NEC, a serious gut inflammation in newborns), Clostridioides difficile infection, and Helicobacter pylori. That means the evidence suggests it may help, but more research is needed to be certain.

The evidence, ingredient by ingredient Saccharomyces Boulardii

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Florastor is generally well tolerated in healthy adults, but the safety data advises against use if you're critically ill, immunocompromised, or in an intensive care setting—particularly if you have central lines, are receiving tube feeding, or are on broad-spectrum antibiotics. In rare cases, the live yeast has caused fungemia (yeast entering the bloodstream), especially under those high-risk conditions.

Uncommonly, people report mild gastrointestinal side effects like stomach cramps, gas, nausea, vomiting, or loss of appetite. Because safety information is limited, talk with your doctor before starting it.

Side effects, ingredient by ingredient Saccharomyces Boulardii

Meds to double-check

Minor interactions only
Known Interaction Concern · database check
Minor only

Only Minor-severity interactions are documented for these ingredients.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Saccharomyces Boulardii.
  • The most serious interaction on file is rated Minor.
  • For scale: 40 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take antifungal medications, double-check with your doctor or pharmacist before starting Florastor—the antifungal could reduce the yeast's effectiveness. For all other medications, no interactions are documented in our data for the ingredients we could check.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Only minor medication interactions are documented, and safety information is well characterized.

Florastor is a probiotic option for people with certain types of diarrhea and is generally tolerated well in healthy adults. If you're critically ill, have a weakened immune system, or are in intensive care, you should avoid it.

Before taking it, check with your doctor or pharmacist, especially if you're on antifungal medications.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Sep 25, 2013.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Florastor Saccharomyces Boulardii Lyo, straight from the product label.

Brand Biocodex
Net contents 50 Capsule(s); 250 mg
Market status On market
Date entered into DSLD Sep 25, 2013
DSLD ID 25700
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Florastor Saccharomyces Boulardii Lyo by Biocodex, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 vegetarian, gluten-free capsule(s)
Maximum serving Sizes:
1 vegetarian, gluten-free capsule(s)
IngredientAmount% DV
Lactose33 mg--
Saccharomyces boulardii lyo250 mg--

Other ingredients: Magnesium Stearate, Hydroxypropyl-Methylcellulose, Titanium Dioxide

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
FDA Statement of Identity

Dietary Supplement

General Statements

#1 PROBIOTIC WORLDWIDE Studied and trusted for over 50 years

~Maintains the balance of the intestinal flora ~Keeps intestines functioning well ~Promotes intestinal health

~Travel Friendly ~Simple Administration ~Appropriate for Lactose Intolerance

Best-selling probiotic worldwide. Available in over 100 countries. Studied and trusted since 1953. References: 1. IMS Data 2010. 2. Pharmacy Today #1 Pharmacists' Recommended OTC, February 2011

Seals/Symbols

Pharmacists' #1 Probiotic Choice2 #1 S. boulardii Biocodex

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Precautions

KEEP OUT OF REACH OF CHILDREN

Storage

DO NOT REFRIGERATE

Brand IP Statement(s)

(C)2011

Suggested/Recommended/Usage/Directions

Suggested use: 1 capsule in the morning, 1 capsule in the evening. How to take: Swallow capsule whole or mix contents of capsule with water, juice, or other noncarbonated drinks. Capsule contents can also be added to applesauce or other soft foods.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Florastor Saccharomyces Boulardii Lyo by Biocodex label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Florastor Saccharomyces Boulardii Lyo label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Florastor Saccharomyces Boulardii Lyo by Biocodex

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 vegetarian, gluten-free capsule(s) Dosage formCapsule Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Lactose

33 mg per serving

Saccharomyces boulardii lyo

Interacts with
40 drugs
250 mg per serving

Saccharomyces boulardii is a beneficial yeast used as a probiotic, with the strongest evidence for preventing and treating certain types of diarrhea,...

Saccharomyces boulardii lyo monograph & interactions

Other (inactive) ingredients: Magnesium Stearate, Hydroxypropyl-Methylcellulose, Titanium Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

Florastor Saccharomyces Boulardii Lyo by Biocodex Drug Interactions

Want to check YOUR meds against Florastor Saccharomyces Boulardii Lyo?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
40Drugs
40 Minor

Ingredients driving the most interactions

Saccharomyces boulardii lyo 40

Individual Drug Interactions

The ingredients in Florastor Saccharomyces Boulardii Lyo interact with 40 drugs. Click any drug to see the details.

1 of the 2 ingredients in Florastor Saccharomyces Boulardii Lyo interact with drugs. Each result below shows which ingredient is responsible. Saccharomyces boulardii lyo

Each ingredient & the kinds of drugs it affects

For each ingredient in Florastor Saccharomyces Boulardii Lyo with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Saccharomyces boulardii lyo1 drug type · 40 drugs

Antifungals

Theoretically, taking antifungals with Saccharomyces boulardii might decrease the effectiveness of Saccharomyces boulardii.
S. boulardii is a live yeast. Therefore, simultaneously taking antifungals might kill a significant number of the organisms.

Likelihood Possible Evidence D
Saccharomyces boulardii lyo full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Florastor Saccharomyces Boulardii Lyo, from the product label.

Biocodex

See all Biocodex products
Name
Biocodex, Inc
City
San Bruno
State
Ca
ZipCode
94066
Phone Number
1-877-356-7787
Pharmacist Counseling Corner

Florastor Saccharomyces Boulardii Lyo by Biocodex: Common Questions

Does Florastor Saccharomyces Boulardii Lyo by Biocodex interact with any medications?
Yes. Based on its ingredients, Florastor Saccharomyces Boulardii Lyo has a known interaction with 40 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Florastor Saccharomyces Boulardii Lyo contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
What is Saccharomyces boulardii and why is it in this product?
Saccharomyces boulardii is a strain of beneficial yeast (a type of probiotic) that may help restore your gut bacteria and ease certain types of diarrhea. It's the active ingredient doing the therapeutic work in Florastor.
Can I take Florastor if I'm on an antifungal medication?
Antifungals can kill the live yeast in this product, which might make it less effective. Talk with your doctor or pharmacist before combining them—they may recommend timing the doses differently or choosing a different approach.
Is Florastor safe for me if I'm immunocompromised?
No. The safety data advises against use if you're critically ill or have a weakened immune system, because in rare cases the live yeast has entered the bloodstream in high-risk patients. Discuss alternatives with your doctor.
Does this product contain anything besides the yeast?
The active ingredient is the yeast itself. There's also lactose in the capsule, plus inactive fillers (magnesium stearate, hydroxypropyl-methylcellulose, and titanium dioxide). If you're sensitive to any of these, check the label or talk with your pharmacist.
What side effects might I notice?
Most people have no side effects, but some have reported mild stomach cramps, gas, nausea, vomiting, or decreased appetite. These are uncommon and usually pass. If they don't improve or get worse, stop and talk with your doctor.
Does Florastor actually work for diarrhea?
The evidence suggests it may help with rotaviral diarrhea, traveler's diarrhea, diarrhea from antibiotics, and a few other gut conditions, but more research is needed to be certain. Results vary person to person.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Florastor Saccharomyces Boulardii Lyo label
Go deeper

The Full Monographs Behind Florastor Saccharomyces Boulardii Lyo’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Saccharomyces Boulardii

Interacts with 40 drugs

Saccharomyces boulardii is a beneficial yeast used as a probiotic, with the strongest evidence for preventing and treating certain types of diarrhea, including antibiotic-associated diarrhea...

Read the full Saccharomyces Boulardii monograph →
Sources

Sources & How We Checked

Florastor Saccharomyces Boulardii Lyo's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 26 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Saccharomyces Boulardii 26 references
  1. Niault M, Thomas F, Prost J, et al. Fungemia due to Saccharomyces species in a patient treated with enteral Saccharomyces boulardii. Clin Infect Dis 1999;28:930.
  2. Pletinex M, Legein J, Vandenplas Y. Fungemia with Saccharomyces boulardii in a 1-year-old girl with protracted diarrhea. J Pediatr Gastroenterol Nutr 1995;21:113-5. DOI
  3. Fredenucci I, Chomarat M, Boucaud C, et al. Saccharomyces boulardii fungemia in a patient receiving ultra-levure therapy. Clin Infect Dis 1998;27:222-3.
  4. Elmer GW, McFarland LV, Surawicz CM, et al. Behaviour of Saccharomyces boulardii in recurrent Clostridium difficile disease patients. Aliment Pharmacol Ther 1999;13:1663-8.
  5. Lewis SJ, Freedman AR. Review article: the use of biotherapeutic agents in the prevention and treatment of gastrointestinal disease. Aliment Pharmacol Ther 1998;12:807-22. PubMed
  6. Cesaro S, Chinello P, Rossi L, Zanesco L. Saccharomyces cerevisiae fungemia in a neutropenic patient treated with Saccharomyces boulardii. Support Care Cancer 2000;8:504-5. PubMed
  7. Hennequin C, Thierry A, Richard GF, et al. Microsatellite typing as a new tool for identification of Saccharomyces cerevisiae strains. J Clin Microbiol 2001;39:551-9.
  8. Plein K, Hotz J. Therapeutic effects of Saccharomyces boulardii on mild residual symptoms in a stable phase of Crohn's disease with special respect to chronic diarrhea - a pilot study. Z Gastroenterol 1993;31:129-34.
  9. Borriello SP, Hammes WP, Holzapfel W, et al. Safety of probiotics that contain lactobacilli or bifidobacteria. Clin Infect Dis 2003;36:775-80. PubMed
  10. Marteau P, Seksik P. Tolerance of probiotics and prebiotics. J Clin Gastroenterol 2004;38:S67-9. PubMed
  11. Munoz P, Bouza E, Cuenca-Estrella M, et al. Saccharomyces cerevisiae fungemia: an emerging infectious disease. Clin Infect Dis 2005;40:1625-34. PubMed
  12. Lherm, T., Monet, C., Nougiere, B., Soulier, M., Larbi, D., Le Gall, C., Caen, D., and Malbrunot, C. Seven cases of fungemia with Saccharomyces boulardii in critically ill patients. Intensive Care Med 2002;28(6):797-801. PubMed
  13. Riquelme, A. J., Calvo, M. A., Guzman, A. M., Depix, M. S., Garcia, P., Perez, C., Arrese, M., and Labarca, J. A. Saccharomyces cerevisiae fungemia after Saccharomyces boulardii treatment in immunocompromised patients. J Clin.Gastroenterol. 2003;36(1):41- PubMed
  14. Cherifi, S., Robberecht, J., and Miendje, Y. Saccharomyces cerevisiae fungemia in an elderly patient with Clostridium difficile colitis. Acta Clin Belg. 2004;59(4):223-224. PubMed
  15. Ellouze O, Berthoud V, Mervant M, Parthiot JP, Girard C. Septic shock due to Sacccaromyces boulardii. Med Mal Infect. 2016;46(2):104-105.
  16. Appel-da-Silva MC, Narvaez GA, Perez LRR, Drehmer L, Lewgoy J. Saccharomyces cerevisiae var. boulardii fungemia following probiotic treatment. Med Mycol Case Rep. 2017;18:15-7. PubMed
  17. Atici S, Soysal A, Karadeniz Cerit K, et al. Catheter-related Saccharomyces cerevisiae Fungemia Following Saccharomyces boulardii Probiotic Treatment: In a child in intensive care unit and review of the literature. Med Mycol Case Rep. 2017;15:33-35. PubMed
  18. Martin IW, Tonner R, Trivedi J, et al. Saccharomyces boulardii probiotic-associated fungemia: questioning the safety of this preventive probiotic's use. Diagn Microbiol Infect Dis. 2017;87(3):286-8. PubMed
  19. Romanio MR, Coraine LA, Maielo VP, Abramczyc ML, Souza RL, Oliveira NF. Saccharomyces cerevisiae fungemia in a pediatric patient after treatment with probiotics. Rev Paul Pediatr 2017;35(3):361-4.
  20. Roy U, Jessani LG, Rudramurthy SM, et al. Seven cases of Saccharomyces fungaemia related to use of probiotics. Mycoses 2017;60(6):375-380.
  21. Romanio MR, Coraine LA, Maielo VP, Abramczyc ML, Souza RL, Oliveira NF. Saccharomyces cerevisiae fungemia in a pediatric patient after treatment with probiotics. Rev Paul Pediatr. 2017 Jul-Sep;35(3):361-364. doi: 10.1590/1984-0462/;2017;35;3;00014.
  22. Flatley EA, Wilde AM, Nailor MD. Saccharomyces boulardii for the prevention of hospital onset Clostridium difficile infection. J Gastrointestin Liver Dis. 2015;24(1):21-4. PubMed
  23. Ventoulis I, Sarmourli T, Amoiridou P, et al. Bloodstream infection by Saccharomyces cerevisiae in two COVID-19 patients after receiving supplementation of Saccharomyces in the ICU. J Fungi (Basel). 2020;6(3):98. PubMed
  24. Wombwell E, Bransteitter B, Gillen LR. Incidence of Saccharomyces cerevisiae fungemia in hospitalised patients administered Saccharomyces boulardii probiotic. Mycoses 2021;64(12):1521-1526.
  25. Rannikko J, Holmberg V, Karppelin M, et al. Fungemia and Other Fungal Infections Associated with Use of Saccharomyces boulardii Probiotic Supplements. Emerg Infect Dis 2021;27(8):2090-6.
  26. Awoyemi A, Mayerhofer C, Felix AS, et al. Rifaximin or Saccharomyces boulardii in heart failure with reduced ejection fraction: Results from the randomized GutHeart trial. EBioMedicine 2021;70:103511. PubMed

See these in context on the Saccharomyces Boulardii monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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