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

Primadophilus Probiotic Ingredients & Drug Interactions

by Nature's Way

Primadophilus Probiotic label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Primadophilus Probiotic 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

Primadophilus Probiotic is a dietary supplement by Nature's Way with 2 active ingredients. Its ingredients are commonly taken for digestive health and balance, diarrhea (including antibiotic-related), vaginal yeast and bacterial infections.Based on those ingredients, 182 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Lactobacillus acidophilus R0418. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Primadophilus Probiotic by Nature's Way

Ask about any prescription or over-the-counter medication and we check it for interactions with Primadophilus Probiotic by Nature's Way — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Primadophilus Probiotic by Nature's Way

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 11, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 2 active ingredients.
  • “Proprietary Probiotic Blend” is a proprietary blend — the label gives one combined amount (340 mg) without saying how much of each component you get.

Primadophilus contains 2 active probiotic ingredients: Lactobacillus acidophilus R0418 and Lactobacillus rhamnosus HA-111. These are live beneficial bacteria designed to support digestive health.

The rest of the capsule is made up of inactive ingredients — potato starch, hypromellose, gellan gum, magnesium stearate, and ascorbic acid — which help hold the formula together and protect the bacteria.

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: supports healthy digestive flora.
  • We looked for evidence on: Antibiotic-associated diarrhea, Clostridioides difficile infection, Constipation, Inflammatory bowel disease (IBD), Irritable bowel syndrome (IBS), Lactose intolerance — 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 Irritable bowel syndrome (IBS).
  • Also on file: Lactobacillus Acidophilus is rated "Insufficient Reliable Evidence To Rate" for Constipation, Inflammatory bowel disease (IBD), Rotaviral diarrhea, Lactose intolerance, and more.

Lactobacillus acidophilus is possibly effective for irritable bowel syndrome (IBS), Helicobacter pylori infection, antibiotic-associated diarrhea, and bacterial vaginosis. The evidence for atopic disease (allergic conditions) is rated as possibly ineffective, and for acute respiratory distress syndrome we don't have enough reliable data to say either way.

We hold no effectiveness data for Lactobacillus rhamnosus HA-111.

The evidence, ingredient by ingredient 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 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.

Lactobacillus acidophilus is generally well tolerated in healthy adults and children. Most people don't experience side effects, but because these are live organisms, there's a small theoretical risk of infection in certain patient groups — your doctor should know your health history before you start.

Gastrointestinal side effects like bloating, gas, mild cramping, or loose stools can occur in some people, though they're uncommon. The safety data is limited, so check with your healthcare provider, especially if you have a compromised immune system or serious underlying illness.

We don't have pregnancy or breastfeeding data on file for Lactobacillus rhamnosus HA-111.

Side effects, ingredient by ingredient 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?
  • 1 of the 1 matched ingredient can interact with medications — Lactobacillus Acidophilus.
  • 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.

The main medication type to double-check is antibiotics — they can reduce how well this probiotic works. Because we couldn't verify Lactobacillus rhamnosus HA-111 against our data, use the search tool on this page to confirm your exact medications are clear.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This probiotic is a reasonable choice if you're looking to support digestive health and have no serious immune problems. If you're taking antibiotics, space them apart from this product.

Run your medication list through the interaction checker before you start, and talk to your pharmacist if you have questions about timing or fit with your health picture.

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 Jan 23, 2025.

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 Primadophilus Probiotic, straight from the product label.

Brand Nature's Way
Barcode (UPC) 033674068007
Net contents 90 Capsule(s)
Market status On market
Date entered into DSLD Jan 23, 2025
DSLD ID 328030
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Children 4 or More Years of Age, 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 Primadophilus Probiotic by Nature's Way, 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)
Servings per container
90
UPC/BARCODE
033674068007
IngredientAmount% DV
Proprietary Probiotic Blend340 mg--
Lactobacillus rhamnosus HA-1110 NP--
Lactobacillus acidophilus R04180 NP--

Other ingredients: Potato Starch, Hypromellose, Gellan Gum, 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.
Formula

Proprietary Probiotic Blend for ages 12+ with L. rhamnosus & L. acidophilus Provides 5 billion CFU per serving

5 billion CFU

Ages 12+

Formulation

Supports healthy digestive flora Guaranteed potency through the date of expiration

Bottled and tested in the USA

For healthy digestive flora Once daily delayed release

Storage

Keep refrigerated

Keep tightly closed. Keep refrigerated to maintain maximum potency.

Keep refrigerated to maintain maximum potency.

General Statements

Explore more products at naturesway.com

Bottle made from 50% post-consumer recycled plastic

Precautions

Keep out of reach of children.

Safety sealed with inner seal. Do not use if seal is broken or missing.

If you are pregnant, nursing, or taking any medications, consult a healthcare professional before use.

Contains milk and soy.

Brand IP Statement(s)

Copyright 2024 Nature's Way Brands, LLC

FDA Disclaimer Statement

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

FDA Statement of Identity

Probiotic Supplement

Suggested/Recommended/Usage/Directions

Recommendation: Adults and children 12 years of age and older, take 1 capsule daily.

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

See for yourself

Primadophilus Probiotic by Nature's Way label

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

Primadophilus Probiotic 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 Primadophilus Probiotic by Nature's Way

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container90 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 Probiotic Blend

340 mg per serving

Other (inactive) ingredients: Potato Starch, Hypromellose, Gellan Gum, Magnesium Stearate, Ascorbic Acid. These complete the product’s ingredient list but are not active constituents.

Interaction report

Primadophilus Probiotic by Nature's Way Drug Interactions

Want to check YOUR meds against Primadophilus Probiotic?

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

Lactobacillus acidophilus R0418 182

Individual Drug Interactions

The ingredients in Primadophilus Probiotic interact with 182 drugs. Click any drug to see the details.

1 of the 2 ingredients in Primadophilus Probiotic interact with drugs. Each result below shows which ingredient is responsible. Lactobacillus acidophilus R0418

Each ingredient & the kinds of drugs it affects

For each ingredient in Primadophilus Probiotic 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.

Lactobacillus acidophilus R04181 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 R0418 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Primadophilus Probiotic, from the product label.

Nature's Way

See all Nature's Way products
Name
Nature's Way Brands, LLC
City
Green Bay
State
WI
ZipCode
54311
Phone Number
1-800-962-8873
Web Address
naturesway.com
Pharmacist Counseling Corner

Primadophilus Probiotic by Nature's Way: Common Questions

Does Primadophilus Probiotic by Nature's Way interact with any medications?
Yes. Based on its ingredients, Primadophilus Probiotic 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?
Primadophilus Probiotic 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.
Can I take this with my antibiotics?
You can take both, but not at the same time. Antibiotics kill the live bacteria in this probiotic, making it less effective. Ask your pharmacist or doctor how far apart to space them — usually a few hours does the job.
Is this safe if I'm pregnant?
The safety data we have shows Lactobacillus acidophilus is possibly safe in pregnancy, but we don't have pregnancy safety information on file for the Lactobacillus rhamnosus strain in this product. Talk with your doctor or pharmacist before starting, especially during pregnancy.
Will this help my IBS?
Lactobacillus acidophilus is rated possibly effective for IBS. That means there's some evidence it may help, but it's not guaranteed — results vary from person to person. Give it a fair trial and see how you feel.
What side effects should I expect?
Most people take this without problems. Some folks notice mild bloating, gas, cramping, or loose stools at first, but these are uncommon and usually temporary. If you have serious immune issues, ask your doctor first because there's a small theoretical risk of infection.
Does this product have fillers?
Yes — the capsule contains potato starch, hypromellose, gellan gum, magnesium stearate, and ascorbic acid, which are inactive ingredients that help keep the formula stable and usable.

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

Not sure if Primadophilus Probiotic 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.

Primadophilus Probiotic label
Go deeper

The Full Monographs Behind Primadophilus Probiotic’s Ingredients

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

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

Primadophilus Probiotic'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 15 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.

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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