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Dietary supplement

Double Strength Acidophilus & Bifidus Ingredients & Drug Interactions

by Natural Factors

Double Strength Acidophilus & Bifidus label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Double Strength Acidophilus & Bifidus 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: Moderate

Double Strength Acidophilus & Bifidus is a dietary supplement by Natural Factors with 3 active ingredients. Its ingredients are commonly taken for digestive health and regularity, diarrhea (including antibiotic-related), irritable bowel syndrome (ibs) symptoms.Based on those ingredients, 182 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Bifidobacterium bifidum, Lactobacillus acidophilus. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Double Strength Acidophilus & Bifidus by Natural Factors

Ask about any prescription or over-the-counter medication and we check it for interactions with Double Strength Acidophilus & Bifidus by Natural Factors — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Double Strength Acidophilus & Bifidus by Natural Factors

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 23, 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 3 of its 3 active ingredients.
  • “Proprietary Synergistic Blend” is a proprietary blend — the label gives one combined amount (10,000,000,000 Unit(s)) without saying how much of each component you get.

This product contains 3 active ingredients: two probiotic bacteria strains (Bifidobacterium bifidum and Lactobacillus acidophilus) and Lactobacillus rhamnosus, plus a proprietary blend. Probiotics are live microorganisms meant to support gut health.

The product also contains inactive ingredients including lactose, whey, goat milk, gelatin, pectin, magnesium stearate, and ascorbic acid (vitamin C).

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: digestive health with beneficial micro-flora.
  • We looked for evidence on: Antibiotic-associated diarrhea, Bacterial vaginosis, Clostridioides difficile infection, Colic, Constipation, Inflammatory bowel disease (IBD) — and 4 related terms.
  • The strongest evidence on file: Lactobacillus Acidophilus is rated "Possibly Effective" for Antibiotic-associated diarrhea (Natural Medicines).
  • Also on file: Lactobacillus Acidophilus is rated "Possibly Effective" for Bacterial vaginosis, Irritable bowel syndrome (IBS).
  • Also on file: Bifidobacterium Bifidum is rated "Possibly Effective" for Irritable bowel syndrome (IBS).

Bifidobacterium bifidum is possibly effective for irritable bowel syndrome (IBS) and respiratory tract infections, but evidence is insufficient for hay fever, Alzheimer disease, and anxiety. Lactobacillus acidophilus is possibly effective for IBS, H. pylori, antibiotic-associated diarrhea, and bacterial vaginosis, though it appears possibly ineffective for atopic disease.

Evidence for Lactobacillus rhamnosus and the synergistic blend together isn't covered in the data we hold.

The evidence, ingredient by ingredient Bifidobacterium Bifidum Lactobacillus Acidophilus

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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Both Bifidobacterium bifidum and Lactobacillus acidophilus are generally well tolerated in healthy adults and children. However, those with weakened immune systems should be cautious, and anyone considering this product should check with their doctor first, since evidence remains limited.

Bloating, flatulence, abdominal pain, and burping have been reported with probiotic use, though these are uncommon; one rare case of vomiting and fever was reported in a child taking both strains together. In critical illness, serious complications like sepsis are extremely rare.

Side effects, ingredient by ingredient Bifidobacterium Bifidum Lactobacillus Acidophilus

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 2 of the 2 matched ingredients can interact with medications — Lactobacillus Acidophilus, Bifidobacterium Bifidum.
  • The most serious interaction on file is rated Moderate.
  • For scale: 182 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.

Antibiotic drugs are the only medication type with documented interactions — a Moderate severity concern. Antibiotics can kill the live organisms in this product, so you'll need to separate their timing.

Ask your doctor or pharmacist exactly how many hours apart to take them.

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. Moderate medication interactions have been identified, and safety information is well characterized.

If you have IBS, recurrent respiratory infections, or certain types of diarrhea or vaginal infections, this product may be worth a conversation with your doctor. The main caution is spacing it away from antibiotics — they'll interfere with each other.

Those with weakened immune systems should check in first. Talk it over with your doctor or pharmacist before starting.

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

Assessment coverage: 2 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 27, 2014.

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 Double Strength Acidophilus & Bifidus, straight from the product label.

Brand Natural Factors
Barcode (UPC) 068958018065
Net contents 180 Capsule(s)
Market status On market
Date entered into DSLD Oct 27, 2014
DSLD ID 38869
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free
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 Double Strength Acidophilus & Bifidus by Natural Factors, 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 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
UPC/BARCODE
068958018065
IngredientAmount% DV
Bifidobacterium bifidum1000000000 {Unit(s)}--
Lactobacillus acidophilus1000000000 {Unit(s)}--
Lactobacillus rhamnosus8000000000 {Unit(s)}--
Proprietary Synergistic Blend10000000000 {Unit(s)}--

Other ingredients: Lactose, Whey, Goat Milk, Gelatin Capsule, Pectin, Magnesium Stearate, Ascorbic Acid

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

10 BILLION ACTIVE CELLS

PROMOTES WELL-BEING & DIGESTIVE HEALTH WITH BENEFICIAL MICRO-FLORA*

Manufactured by Natural Factors to ensure safety and potency in accordance with Good Manufacturing Practices (GMP) of the FDA and Health Canada.

Guaranteed minimum 10 billion active cells per capsule at expiry date. Guaranteed minimum 13 billion active cells per capsule at manufacture date.

PRODUCT OF CANADA

Recyclable container and label.

Seals/Symbols

WITH GOAT MILK

Purity&Potency Guaranteed

Formula

May contain traces of soy from fermentation process.

This synergistic combination supports intestinal tract health and contains goat’s milk, an excellent growth factor for beneficial micro-flora.* These cultures are freeze-dried to ensure long-term stability and maximum potency.*

Suggested/Recommended/Usage/Directions

Suggested usage: 1 capsule 1–3 times per day or as directed by a health professional. When taking antibiotics, wait two hours before ingesting probiotics.

Precautions

Keep out of the reach of children.

Sealed for your protection. Do not use if seal is broken.

May contain traces of soy from fermentation process.

Formulation

Contains no artificial colors, preservatives, or sweeteners; no starch, wheat, gluten, corn, egg, fish, shellfish, tree nuts, or GMOs.

Storage

For freshness, store in a cool, dry place.

FOR MAXIMUM POTENCY, REFRIGERATE.

FDA Disclaimer Statement

* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

General

R3

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

See for yourself

Double Strength Acidophilus & Bifidus by Natural Factors label

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

Double Strength Acidophilus & Bifidus 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 Double Strength Acidophilus & Bifidus by Natural Factors

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 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.

Proprietary Synergistic Blend

10000000000 {Unit(s)} per serving

Other (inactive) ingredients: Lactose, Whey, Goat Milk, Gelatin Capsule, Pectin, Magnesium Stearate, Ascorbic Acid. These complete the product’s ingredient list but are not active constituents.

Interaction report

Double Strength Acidophilus & Bifidus by Natural Factors Drug Interactions

Want to check YOUR meds against Double Strength Acidophilus & Bifidus?

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
182Drugs
182 Moderate

Ingredients driving the most interactions

Bifidobacterium bifidum 182
Lactobacillus acidophilus 182

Individual Drug Interactions

The ingredients in Double Strength Acidophilus & Bifidus interact with 182 drugs. Click any drug to see the details.

2 of the 3 ingredients in Double Strength Acidophilus & Bifidus interact with drugs. Each result below shows which ingredient is responsible. Bifidobacterium bifidum Lactobacillus acidophilus

Each ingredient & the kinds of drugs it affects

For each ingredient in Double Strength Acidophilus & Bifidus with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Bifidobacterium bifidum1 drug type · 182 drugs

Antibiotic Drugs

Theoretically, taking Bifidobacterium. bifidum with antibiotic drugs might decrease the effectiveness of B. bifidum.
Since B. bifidum preparations usually contain live and active organisms, simultaneously taking antibiotics might kill a significant number of the organisms. Tell patients to separate administration of antibiotics and B. bifidum preparations by at least 2 hours.

Likelihood Probable Evidence D
Bifidobacterium bifidum full monograph & interactions

Lactobacillus acidophilus1 drug type · 182 drugs

Antibiotic Drugs

Theoretically, taking Lactobacillus acidophilus with antibiotic drugs might decrease the effectiveness of L. acidophilus.
L. acidophilus preparations usually contain live and active organisms. Therefore, simultaneously taking antibiotics might kill a significant number of the organisms. Tell patients to separate administration of antibiotics and L. acidophilus preparations by at least two hours.

Likelihood Probable Evidence D
Lactobacillus acidophilus full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Double Strength Acidophilus & Bifidus, from the product label.

Natural Factors

See all Natural Factors products
Name
Natural Factors Canada
Pharmacist Counseling Corner

Double Strength Acidophilus & Bifidus by Natural Factors: Common Questions

Does Double Strength Acidophilus & Bifidus by Natural Factors interact with any medications?
Yes. Based on its ingredients, Double Strength Acidophilus & Bifidus has a known interaction with 182 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Double Strength Acidophilus & Bifidus contains 3 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.
Will this interfere with my antibiotic?
Yes — antibiotics can kill the live bacteria in this product, making it less effective. You'll need to space them apart. Ask your pharmacist or doctor how many hours to separate them.
Is this safe if my immune system is weak?
The data advises caution if your immune system is compromised. Talk with your doctor before starting, since live probiotics carry a theoretical risk in that situation.
Can I take this while pregnant?
Both main ingredients are rated possibly safe in pregnancy, but evidence is limited. Check with your doctor to see if it's right for your situation.
What side effects might I notice?
Bloating, gas, and abdominal discomfort are the most common complaints with probiotics, though they're not always reported with this specific strain. These effects are usually mild and uncommon.
Will this actually help my IBS?
Both Bifidobacterium bifidum and Lactobacillus acidophilus are possibly effective for IBS based on available evidence, but results vary from person to person.
What is Lactobacillus rhamnosus supposed to do?
We don't have effectiveness data on file for Lactobacillus rhamnosus alone, so I can't tell you what role it plays in this blend from the information we hold.

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

Not sure if Double Strength Acidophilus & Bifidus is safe with your meds?

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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.

Double Strength Acidophilus & Bifidus label
Go deeper

The Full Monographs Behind Double Strength Acidophilus & Bifidus’s Ingredients

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

Herb & supplement monograph

Bifidobacterium Bifidum

Interacts with 182 drugs

Bifidobacterium bifidum is a 'friendly' bacteria (probiotic) that naturally lives in the human gut and is taken to support digestion and gut balance. Some evidence suggests probiotics may he...

Read the full Bifidobacterium Bifidum monograph → Herb & supplement monograph

Lactobacillus Acidophilus

Interacts with 182 drugs

Lactobacillus acidophilus is a 'friendly' bacterium used as a probiotic to support gut and vaginal health. It is generally well tolerated in healthy people, and there is reasonable evidence...

Read the full Lactobacillus Acidophilus monograph →
Sources

Sources & How We Checked

Double Strength Acidophilus & Bifidus'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 22 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.

Bifidobacterium Bifidum 7 references
  1. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  2. Xiao JZ, Takahashi S, Odamaki T, et al. Antibiotic susceptibility of bifidobacterial strains distributed in the Japanese market. Biosci Biotechnol Biochem. 2010;74(2):336-42. PubMed
  3. Rerksuppaphol S, Rerksuppaphol L. Randomized controlled trial of probiotics to reduce common cold in schoolchildren. Pediatr Int. 2012;54(5):682-7. PubMed
  4. Karamali M, Dadkhah F, Sadrkhanlou M, et al. Effects of probiotic supplementation on glycaemic control and lipid profiles in gestational diabetes: a randomized, double-blind, placebo-controlled trial. Diabetes Metab 2016;42(4):234-41. PubMed
  5. Badehnoosh B, Karamali M, Zarrati M, et al. The effects of probiotic supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in gestational diabetes. J Matern Fetal Neonatal Med. 2018 May;31(9):1128-1136.
  6. Pruccoli G, Silvestro E, Pace Napoleone C, Aidala E, Garazzino S, Scolfaro C. Are probiotics safe? Bifidobacterium bacteremia in a child with severe heart failure. Infez Med. 2019;27(2):175-178.
  7. Esaiassen E, Hjerde E, Cavanagh JP, Simonsen GS, Klingenberg C; Norwegian Study Group on Invasive Bifidobacterial Infections. Bifidobacterium bacteremia: Clinical characteristics and a genomic approach to assess pathogenicity. J Clin Microbiol. 2017;55(7) PubMed

See these in context on the Bifidobacterium Bifidum monograph →

Lactobacillus Acidophilus 15 references
  1. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  2. Begtrup LM, de Muckadell OB, Kjeldsen J, Christensen RD, Jarbøl DE. Long-term treatment with probiotics in primary care patients with irritable bowel syndrome--a randomised, double-blind, placebo controlled trial. Scand J Gastroenterol 2013;48(10):1127-35 PubMed
  3. Chatterjee S, Kar P, Das T, Ray S, Gangulyt S, Rajendiran C, Mitra M. Randomised placebo-controlled double blind multicentric trial on efficacy and safety of Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 for prevention of antibiotic-associated
  4. Shavakhi A, Tabesh E, Yaghoutkar A, Hashemi H, Tabesh F, Khodadoostan M,Minakari M, Shavakhi S, Gholamrezaei A. The effects of multistrain probiotic compound on bismuth-containing quadruple therapy for Helicobacter pylori infection: a randomized placebo-c
  5. Karamali M, Dadkhah F, Sadrkhanlou M, et al. Effects of probiotic supplementation on glycaemic control and lipid profiles in gestational diabetes: a randomized, double-blind, placebo-controlled trial. Diabetes Metab 2016;42(4):234-41. PubMed
  6. Badehnoosh B, Karamali M, Zarrati M, et al. The effects of probiotic supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in gestational diabetes. J Matern Fetal Neonatal Med. 2018 May;31(9):1128-1136.
  7. Kumar S, Kumar R, Rohilla L, Jacob N, Yadav J, Sachdeva N. A high potency multi-strain probiotic improves glycemic control in children with new-onset type 1 diabetes mellitus: A randomized, double-blind, and placebo-controlled pilot study. Pediatr Diabete
  8. Shahriari A, Karimi E, Shahriari M, Aslani N, Khooshideh M, Arab A. The effect of probiotic supplementation on the risk of gestational diabetes mellitus among high-risk pregnant women: A parallel double-blind, randomized, placebo-controlled clinical trial PubMed
  9. Xiao SD, Zhang DZ, Lu H, et al. Multicenter, randomized, controlled trial of heat-killed Lactobacillus acidophilus LB in patients with chronic diarrhea. Adv Ther. 2003;20(5):253-60.
  10. Rossi F, Amadoro C, Gasperi M, Colavita G. Lactobacilli infection case reports in the last three years and safety implications. Nutrients. 2022;14(6):1178. PubMed
  11. Ozer M, Goksu SY, Shahverdiani A, Mustafa M. Lactobacillus acidophilus-induced endocarditis and associated splenic abscess. Case Rep Infect Dis 2020;2020:1382709.
  12. Sadrin S, Sennoune S, Gout B, et al. A 2-strain mixture of Lactobacillus acidophilus in the treatment of irritable bowel syndrome: A placebo-controlled randomized clinical trial. Dig Liver Dis 2020;52(5):534-540. PubMed
  13. Stoffer JN, Slingsby TJ, Giuliari GP. Lactobacillus acidophilus endophthalmitis after intravitreal bevacizumab injection requiring intraocular lens explantation. Can J Ophthalmol 2022;57(1):e21-e22. PubMed
  14. Cukovic-Cavka S, Likic R, Francetic I, Rustemovic N, Opacic M, Vucelic B. Lactobacillus acidophilus as a cause of liver abscess in a NOD2/CARD15-positive patient with Crohn's disease. Digestion 2006;73(2-3):107-10.
  15. Hui J, Ren Y, Wang Y, Han Q. Lactobacillus acidophilus endophthalmitis postcataract operation: A case report with a literature review. Ocul Immunol Inflamm 2023.

See these in context on the Lactobacillus Acidophilus 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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