Daily gut routine
Pure TheraPro Rx Saccharomyces 10B
A single-ingredient capsule of the probiotic yeast Saccharomyces boulardii, strain CNCM I-3799, at 10 billion CFU per two capsules.
- Format
- Capsule, once a day
- Type
- Probiotic
- Cost
- $0.50 a day
- Customer rating
- 4.6 out of 5 from 4,189 ratings from Amazon
What customers consistently report
- Working for loose stools and after antibiotics at about half the price of Florastor
- A one-ingredient capsule with no fillers or magnesium stearate
- An easy-to-swallow capsule
Those are the themes that recur across the reviews. Moderate review confidence — Amazon shows 4.6 from 4,189 independent ratings and the brand’s own page shows 4.8 from 173 reviews, but there is no Trustpilot profile or Better Business Bureau listing for the brand.
Why it might work
Saccharomyces boulardii is a yeast, so antibiotics do not kill it, which is why it is the usual probiotic taken alongside an antibiotic course or while traveling. It is thought to bind some bacterial toxins, support the gut lining and calm the inflammatory response to an infection, and it passes out of the gut within days of stopping. The brand says this strain survives stomach acid and bile and releases proteases that help neutralize microbial toxins; those claims rest on strain data and a laboratory study, not on trials of this product. The label does not let you check how many live cells remain at expiry, and the directions across the label, brand page and listing give different daily amounts. Live yeast is not advised for people with severe immune suppression, which the label states.
What the research supports
No trial of this product was found. Its strain, CNCM I-3799, was tested in one placebo-controlled trial of 100 children with acute diarrhea at 10 billion CFU a day, the label’s serving, and recovery was 65.8 hours against 95.3 on placebo. Most of the adult trials behind the yeast’s reputation used the Florastor strain, CNCM I-745, and a 2012 European Food Safety Authority review found the evidence insufficient to show that I-3799 is identical to it. Across 21 trials in 4,780 people, S. boulardii cut antibiotic-associated diarrhea from 18.7% to 8.5%, but that is class-level evidence.
What the label discloses
The strain is printed as a deposited-strain code with its trademarked name, and the capsule holds nothing else. The panel states 10 billion CFU per two capsules without saying whether that is at manufacture or at expiry, though the brand says full potency is guaranteed until expiration. The brand links a certificate of analysis for one lot with microbial and heavy-metal results, but the CFU line on it is marked as confirmed by the manufacturing process and no outside laboratory is named. An earlier label of the same product printed a different strain code.
Who this tends to suit
We match this product to people reporting loose stools, irregular bowel habits, general abdominal discomfort, bloating and gas. It fits someone whose priority is resetting after a course of antibiotics or an upset or day-to-day comfort. Whether it is the best fit for you depends on the rest of your answers — what you have already tried, what format you will take, and anything that has to be ruled out.
Where it may not fit
The label supports gluten-free, dairy-free, vegan and no added sweeteners. We flag this product for anyone pregnant or breastfeeding or taking prescription medication, and the quiz removes it rather than recommending it in those cases. That is a caution about who should be deciding, not a claim about the product. A capsule only works if you will take it once a day, every day.
Side effects and what to be aware of
About 4% of Amazon ratings are one or two stars. Amazon’s summary shows 34 negative side-effect mentions out of 57, including stomach pain, bloating, nausea and heartburn. The label advises people taking medication, children and anyone pregnant or nursing to consult a healthcare practitioner, says not to use it with severe immune suppression, and says to take it at least two hours apart from antifungal medicines.
Common questions
Does Pure TheraPro Rx Saccharomyces 10B work?
No trial of this product was found. Its strain, CNCM I-3799, was tested in one trial of 100 children with acute diarrhea at 10 billion CFU a day, where recovery was 65.8 hours against 95.3 on placebo; no adult trial of this strain alone was found. Across 21 trials in 4,780 people, S. boulardii cut antibiotic-associated diarrhea from 18.7% to 8.5%, and most Amazon reviewers who say it worked mention antibiotics, diarrhea or C. difficile recovery.
Is Pure TheraPro Rx Saccharomyces safe, and what are the side effects?
The label advises people taking medication, children, and pregnant or lactating women to consult a healthcare practitioner, says not to use it with severe immune suppression, and says to take it at least two hours before or after antifungal medicines. On Amazon, 34 of 57 side-effect mentions are negative, including stomach pain, bloating, nausea and heartburn.
How much does Pure TheraPro Rx Saccharomyces 10B cost?
A 120-capsule bottle holds 60 servings of two capsules. It is $29.97 on Amazon, which is $0.50 a day at one serving a day, or $0.45 with Subscribe & Save. The brand site charges $28.97 ($0.48 a day), or $24.62 with a 15% subscription; the brand and Amazon directions allow up to two servings a day, which doubles the daily cost.
Pure TheraPro Rx Saccharomyces vs Florastor: which has more evidence?
Florastor prints the strain CNCM I-745 and 250 mg per capsule, and most of the trials the yeast is known for used I-745. Pure TheraPro prints CNCM I-3799 at 10 billion CFU per two capsules, which has one pediatric diarrhea trial, and a 2012 European Food Safety Authority review found it unproven that the two strains are identical. Florastor costs about $1.31 a day against $0.50 here, and Florastor contains lactose and magnesium stearate while this capsule holds only the yeast.
Does Pure TheraPro Rx have a refund policy, and is it tested?
The brand’s product page says 90-day return guarantee but its policy page says 60 days, with store credit only for opened bottles, a 25% restocking fee on refunds of unopened first purchases, and one product per household. On Amazon the item is non-returnable unless damaged or defective. The brand links a certificate of analysis for one lot showing negative microbial tests and heavy metals under its limits, but it names no outside laboratory.
Before you take this. Speak to a doctor or pharmacist first if you are pregnant or breastfeeding, or taking prescription medication. Nothing on this page is medical advice, and no supplement diagnoses, treats, cures or prevents disease.
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Related reading
Background on how this type of product works, read from the trial evidence.