Interactions on record — worth a quick check against your medications. Based on 1 of 3 ingredients. Check your meds →
Dietary supplement

Women's Probiotic 20 Billion Ingredients & Drug Interactions

by NOW

Women's Probiotic 20 Billion label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Women's Probiotic 20 Billion 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

Women's Probiotic 20 Billion is a dietary supplement by NOW with 3 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 La-14. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Women's Probiotic 20 Billion by NOW

Ask about any prescription or over-the-counter medication and we check it for interactions with Women's Probiotic 20 Billion by NOW — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Women's Probiotic 20 Billion by NOW

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 3 active ingredients.
  • “Blend of Probiotic Bacteria” is a proprietary blend — the label gives one combined amount (139 mg) without saying how much of each component you get.

This product contains 3 active ingredients: two named probiotic strains (Lactobacillus acidophilus La-14 and Lactobacillus rhamnosus HN-001) plus Bifidobacterium lactis HN-19, all delivering live beneficial bacteria to support your gut. The remaining ingredients are inactive — microcrystalline cellulose, hypromellose, magnesium stearate, and silicon dioxide — which are the capsule material and binders that hold everything together.

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: women's health and immune support.
  • We looked for evidence on: Bacterial vaginosis, Vaginal candidiasis, Respiratory tract infections, Antibiotic-associated diarrhea, Lactose intolerance, Vaginal pH balance — and 2 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.
  • Also on file: Lactobacillus Acidophilus is rated "Insufficient Reliable Evidence To Rate" for Respiratory tract infections, Lactose intolerance, Vaginal candidiasis.

Lactobacillus acidophilus has possibly effective evidence for irritable bowel syndrome (IBS), bacterial vaginosis, Helicobacter pylori infection, and antibiotic-associated diarrhea — meaning the research suggests it may help, but the evidence isn't conclusive. It's rated possibly ineffective for atopic disease and there isn't enough reliable evidence to rate it for acute respiratory distress syndrome (ARDS).

The effectiveness data we hold covers only L. acidophilus; we don't have ratings for the other two strains in this blend.

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. Gastrointestinal side effects like abdominal discomfort, gas, bloating, and diarrhea can occur when taking probiotics, but these are uncommon.

In rare cases, live probiotic organisms have been linked to serious infections (like sepsis or bacteremia) mostly in people whose health is already compromised; most cases appear to involve bacteria that translocated from elsewhere in the body. Since the data on this product are limited, check with your doctor or pharmacist before use — especially if you have a weakened immune system or serious underlying illness.

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.

Antibiotic drugs are the main concern — they can reduce how well the L. acidophilus in this product works if you take them at the same time. Space your antibiotic and this probiotic several hours apart.

For the other two bacterial strains (Bifidobacterium lactis HN-19 and Lactobacillus rhamnosus HN-001), we don't have interaction data available, so ask your pharmacist to double-check those against your medications as well.

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 may help with IBS, antibiotic-associated diarrhea, bacterial vaginosis, or Helicobacter pylori infection if the research holds up for you. If you take antibiotics, space them several hours apart from this product so the bacteria don't get killed off.

Talk to your pharmacist before starting, particularly if your immune system is compromised.

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

Assessment coverage: 1 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jul 25, 2024.

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 Women's Probiotic 20 Billion, straight from the product label.

Brand NOW
Barcode (UPC) 733739029065
Net contents 50 Veg Capsule(s)
Market status On market
Date entered into DSLD Jul 25, 2024
DSLD ID 314222
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Kosher, Pregnant Women, Adult Female (18 - 50 Years), Lactating
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 Women's Probiotic 20 Billion by NOW, 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 Veg Capsule(s)
Maximum serving Sizes:
1 Veg Capsule(s)
Servings per container
50
UPC/BARCODE
733739029065
IngredientAmount% DV
Blend of Probiotic Bacteria139 mg--
Lactobacillus acidophilus La-140 NP--
Bifidobacterium lactis HN-190 NP--
Lactobacillus rhamnosus HN-0010 NP--

Other ingredients: Microcrystalline Cellulose, Hypromellose, Magnesium Stearate, Silicon 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.
Suggested/Recommended/Usage/Directions

Suggested Usage: Take 1 capsule daily.

Storage

Store in a cool, dry place to maintain potency.

Formula

NOW Women’s Probiotic has been specially formulated using three clinically tested probiotic strains to support women’s health through every stage of life.

This product features L. rhamnosus HN001 and L. acidophilus La-14 which have been shown to colonize the vaginal tract and help to maintain healthy vaginal pH when taken orally. Both the B. lactis HN019 and HN001 strains may help to support healthy immune system function in pregnant and nursing women. HN019 also supports GI regularity and reduces occasional gas and bloating.

These specialized strains also support healthy, balanced immune system function in women of all ages.

Triangle K (Kosher)

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

Caution: Consult physician if pregnant/nursing, taking medication (especially immune-suppressing drugs), or have a medical condition (especially if immune system is compromised).

Keep out of reach of children.

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish, tree nut or sesame ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

Seals/Symbols

GMP Quality Assured

Triangle K (Kosher)

Strain verified

Formulation

Feminine Flora Balance Supports Vaginal Health Reduces Occasional Bloating

Vegetarian/Vegan

Made and quality tested in the USA with globally sourced ingredients.

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish, tree nut or sesame ingredients.

The probiotic strains in this product have been identity-verified using DNA-fingerprinting technology.

FDA Statement of Identity

A Dietary Supplement

General Statements

Digestive Family owned since 1968.

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

See for yourself

Women's Probiotic 20 Billion by NOW label

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

Women's Probiotic 20 Billion 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 Women's Probiotic 20 Billion by NOW

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

Serving size1 Veg Capsule(s) Dosage formCapsule Servings per container50 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.

Blend of Probiotic Bacteria

139 mg per serving

Other (inactive) ingredients: Microcrystalline Cellulose, Hypromellose, Magnesium Stearate, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

Women's Probiotic 20 Billion by NOW Drug Interactions

Want to check YOUR meds against Women's Probiotic 20 Billion?

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 La-14 182

Individual Drug Interactions

The ingredients in Women's Probiotic 20 Billion interact with 182 drugs. Click any drug to see the details.

1 of the 3 ingredients in Women's Probiotic 20 Billion interact with drugs. Each result below shows which ingredient is responsible. Lactobacillus acidophilus La-14

Each ingredient & the kinds of drugs it affects

For each ingredient in Women's Probiotic 20 Billion 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 La-141 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 La-14 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Women's Probiotic 20 Billion, from the product label.

NOW

See all NOW products
Name
NOW FOODS
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
nowfoods.com
Pharmacist Counseling Corner

Women's Probiotic 20 Billion by NOW: Common Questions

Does Women's Probiotic 20 Billion by NOW interact with any medications?
Yes. Based on its ingredients, Women's Probiotic 20 Billion 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?
Women's Probiotic 20 Billion 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.
Can I take this probiotic while I'm on antibiotics?
You can take both, but not at the same time. Antibiotics kill the live bacteria in this product, making it less effective. Space them several hours apart — ask your pharmacist for the best timing with your specific antibiotic.
Will this help my IBS or diarrhea?
Lactobacillus acidophilus has possibly effective evidence for both IBS and antibiotic-associated diarrhea, meaning research suggests it may help, but it's not guaranteed. Results vary from person to person.
What are the side effects?
Gas, bloating, abdominal discomfort, and diarrhea can happen when you start probiotics, but they're uncommon. In very rare cases, live probiotic bacteria have caused serious infections in people with weakened immune systems.
Is this safe if I'm pregnant or breastfeeding?
We don't have pregnancy or breastfeeding safety data on file for this product. Talk to your doctor or midwife before starting — they can advise you based on your individual situation.
What does each strain in this blend do?
We have effectiveness data for Lactobacillus acidophilus (possibly effective for IBS, diarrhea, bacterial vaginosis, and H. pylori). The other two strains in the blend don't have published effectiveness ratings in our data.

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.

Women's Probiotic 20 Billion label
Go deeper

The Full Monographs Behind Women's Probiotic 20 Billion’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

Women's Probiotic 20 Billion'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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