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

Bilberry 40 mg Ingredients & Drug Interactions

by Natural Factors HerbalFactors

Bilberry 40 mg label
See full label image
Capsule Category: Botanical
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 Bilberry 40 mg 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

Bilberry 40 mg is a dietary supplement by Natural Factors HerbalFactors with 2 active ingredients. Its ingredients are commonly taken for eye and vision health, antioxidant support, diarrhea and digestive upset.Based on those ingredients, 275 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Bilberry extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Bilberry 40 mg by Natural Factors HerbalFactors

Ask about any prescription or over-the-counter medication and we check it for interactions with Bilberry 40 mg by Natural Factors HerbalFactors — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Bilberry 40 mg by Natural Factors HerbalFactors

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 16, 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.
  • “Bilberry extract” is listed as a grouped ingredient — the label gives one combined amount (40 mg) without saying how much of each component you get.

This product contains 2 active ingredients: anthocyanidins and bilberry extract (delivered as bilberry concentrate). Anthocyanidins are the pigments that give bilberry its deep blue-purple color and are thought to be responsible for its effects.

The other ingredient is a gelatin capsule, which is the capsule itself.

Does it work?

Leans against
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
Leans against

The strongest graded evidence we hold for the stated purpose leans against a benefit.

Why this rating?
  • The label markets this product for: healthy eye function and nighttime visual acuity.
  • We looked for evidence on: Night vision, Asthenopia (eye strain), Age-related macular degeneration (AMD), Cataracts, Diabetic retinopathy, Dry eye — and 4 related terms.
  • The closest evidence on file: Bilberry is rated "Possibly Ineffective" for Night vision (Natural Medicines).
  • Also on file: Bilberry is rated "Insufficient Reliable Evidence To Rate" for Age-related macular degeneration (AMD), Cataracts, Diabetic retinopathy, Dry eye, and more.

The evidence for bilberry's benefits is limited. Night vision is possibly ineffective — meaning the data don't support that claim.

For other uses we hold data on — age-related cognitive decline, age-related macular degeneration, atherosclerosis, high cholesterol, and chronic venous insufficiency — there isn't enough reliable evidence to rate whether it works. The research simply isn't established well enough for us to say either way.

The evidence, ingredient by ingredient Bilberry

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.

Bilberry fruit eaten as food is generally well tolerated, but the safety data for concentrated supplements like this one is limited and long-term safety isn't well studied. The main side effects from oral use are dark-colored stools, flatulence, and stomach discomfort.

In studies, a small number of participants reported mild-to-moderate gas and temporary gastrointestinal upset. Be aware that bilberry can turn your stool and tongue dark blue or black — this is harmless but can be startling.

Pregnancy and lactation: bilberry is rated likely safe during pregnancy and breastfeeding, though supplement evidence is limited.

Side effects, ingredient by ingredient Bilberry

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 — Bilberry.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications.
  • For scale: 275 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.

Before you take this product, double-check with your pharmacist or doctor if you're on blood thinners or antiplatelet drugs (like warfarin, aspirin, or clopidogrel), diabetes medications, or the cancer drug erlotinib. Altogether, these interactions span 275 individual medications.

We have no interaction data for anthocyanidins, so mention that ingredient specifically when you check.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with graded evidence leaning against its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Bilberry 40 mg might interest you if you're exploring natural options for eye health, but the evidence for most uses is weak or absent. If you take blood thinners, diabetes medications, or erlotinib (Tarceva), you'll want to check with your doctor or pharmacist before adding this — the interaction risk is real.

Talk it over with your own healthcare provider to see if it makes sense for your situation.

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 Jul 25, 2017.

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 Bilberry 40 mg, straight from the product label.

Brand Natural Factors HerbalFactors
Barcode (UPC) 068958041605
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Jul 25, 2017
DSLD ID 76290
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar 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 Bilberry 40 mg by Natural Factors HerbalFactors, 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
068958041605
IngredientAmount% DV
Anthocyanidins10 mg--
Bilberry extract40 mg--
Bilberry concentrate305 mg--

Other ingredients: Gelatin capsule

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.
Seals/Symbols

isura Non-GMO - Mass spec Documentation - Lab tested

Purity & potency guaranteed

Suggested/Recommended/Usage/Directions

Suggested Usage: 1 capsule 1–3 times per day or as directed by a health professional.

Precautions

Cautions: As with any supplement, consult your health professional before use if you are pregnant, breastfeeding or trying to conceive, or if you are taking medication, have a medical condition, or anticipate a surgery.

Keep out of the reach of children.

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

Formula

Bilberry extract is standardized to 25% of the beneficial flavonoid anthocyanidin in a synergistic base of whole bilberry concentrate.

25% Anthocyanidins

General Statements

Bilberry extract is specifically beneficial for healthy eye function, especially nighttime visual acuity. Manufactured by Natural Factors to ensure safety and potency in accordance with Good Manufacturing Practices (GMP) of the FDA and Health Canada.

Product of Canada Recyclable container and label.

Support for vision

Formulation

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

Storage

For freshness, store in a cool, dry place.

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.

FDA Statement of Identity

Dietary Supplement

General

R4

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

See for yourself

Bilberry 40 mg by Natural Factors HerbalFactors label

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

Bilberry 40 mg 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 Bilberry 40 mg by Natural Factors HerbalFactors

These are the 2 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.

Bilberry extract

Interacts with
275 drugs
40 mg per serving

Bilberry is a blueberry-like fruit rich in antioxidant plant compounds called anthocyanins, and it has a long history of traditional use for eye healt...

Bilberry extract monograph & interactions
  • › Anthocyanidins

Bilberry concentrate

Interacts with
275 drugs
305 mg per serving

Bilberry is a blueberry-like fruit rich in antioxidant plant compounds called anthocyanins, and it has a long history of traditional use for eye healt...

Bilberry concentrate monograph & interactions

Other (inactive) ingredients: Gelatin capsule. These complete the product’s ingredient list but are not active constituents.

Interaction report

Bilberry 40 mg by Natural Factors HerbalFactors Drug Interactions

Want to check YOUR meds against Bilberry 40 mg?

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
275Drugs
275 Moderate

Ingredients driving the most interactions

Bilberry extract 275

Individual Drug Interactions

The ingredients in Bilberry 40 mg interact with 275 drugs. Click any drug to see the details.

1 of the 2 ingredients in Bilberry 40 mg interact with drugs. Each result below shows which ingredient is responsible. Bilberry extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Bilberry 40 mg 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.

Bilberry extract4 drug types · 275 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, bilberry fruit extract might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro, animal, and clinical research suggest that anthocyanidin extracts from bilberry can inhibit platelet aggregation.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, bilberry leaf or fruit extract may increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal research suggests that bilberry leaf extract might have blood glucose-lowering activity. Also, one small clinical trial in patients with type 2 diabetes shows that taking bilberry fruit extract 470 mg as a single dose prior to an oral glucose tolerance test lowers plasma glucose levels when compared with placebo.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, bilberry fruit extract might decrease levels of drugs metabolized by CYP2E1.
Animal research shows that exposure to small concentrations of bilberry extract in drinking water for around one month increased CYP2E1 activity by 31%. However, exposure over a 2-month period did not increase CYP2E1 activity. This effect has not been reported in humans.

Likelihood Possible Evidence D
Erlotinib (Tarceva)

Theoretically, bilberry fruit extract might reduce the efficacy of erlotinib.
In vitro research suggests that bilberry fruit extract and its constituents, delphinidin and delphinidin-3-O-glucoside, inhibit the activity of erlotinib. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Bilberry extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Bilberry 40 mg, from the product label.

Natural Factors HerbalFactors

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

Bilberry 40 mg by Natural Factors HerbalFactors: Common Questions

Does Bilberry 40 mg by Natural Factors HerbalFactors interact with any medications?
Yes. Based on its ingredients, Bilberry 40 mg has a known interaction with 275 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Bilberry 40 mg 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.
Does bilberry actually help with night vision?
The evidence says it's likely ineffective for that. While it's a popular claim, research doesn't back it up well enough for us to recommend it for that purpose.
What are the side effects?
Most people tolerate it well. The common ones are dark stools, gas, and stomach discomfort. Be aware your stool and tongue may turn dark blue or black — it's harmless but noticeable. In studies, a small number of people reported mild-to-moderate gas or temporary stomach upset.
Can I take this while pregnant or breastfeeding?
Bilberry is rated likely safe during pregnancy and breastfeeding. That said, supplement research is limited, so it's smart to run it by your doctor or midwife first.
What's actually in this — what does anthocyanidins mean?
Anthocyanidins are the natural pigments that make bilberry dark blue-purple. They're thought to be the active compounds that give the supplement its effects. This product contains anthocyanidins plus bilberry extract.
How much evidence is there that this works?
Not much for most uses. Age-related eye disease, cognitive decline, and cholesterol all have insufficient evidence. Night vision is rated likely ineffective. The research just isn't there yet to say it reliably helps with any of those.

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

Not sure if Bilberry 40 mg is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.

Bilberry 40 mg label
Go deeper

The Full Monographs Behind Bilberry 40 mg’s Ingredients

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

Herb & supplement monograph

Bilberry

Interacts with 275 drugs

Bilberry is a blueberry-like fruit rich in antioxidant plant compounds called anthocyanins, and it has a long history of traditional use for eye health, circulation, and mild diarrhea. While...

Read the full Bilberry monograph →
Sources

Sources & How We Checked

Bilberry 40 mg'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 14 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.

Bilberry 14 references
  1. Cignarella A, Nastasi M, Cavalli E, Puglisi L. Novel lipid-lowering properties of Vaccinium myrtillus L. leaves, a traditional antidiabetic treatment, in several models of rat dyslipidaemia: a comparison with ciprofibrate. Thromb Res 1996;84:311-22. PubMed
  2. Morazzoni P, Magistretti MJ. Activity of Myrtocyan, an anthosyanoside complex from Vaccinium myrtillus (VMA), on platelet aggregation and adhesiveness. Fitoterapia 1990;61:13-21.
  3. Erlund, I., Koli, R., Alfthan, G., Marniemi, J., Puukka, P., Mustonen, P., Mattila, P., and Jula, A. Favorable effects of berry consumption on platelet function, blood pressure, and HDL cholesterol. Am J Clin Nutr 2008;87(2):323-331. PubMed
  4. Hawrelak, J. A. and Myers, S. P. Effects of two natural medicine formulations on irritable bowel syndrome symptoms: a pilot study. J Altern Complement Med 2010;16(10):1065-1071. PubMed
  5. Morazzoni P and Magistretti MJ. Effects of Vaccinium myrtillus anthocyanosides on prostacyclin-like activity in rat arterial issue. Fitoterapia 1986;57:11-14.
  6. Pulliero G, Montin S, Bettini V, and et al. Ex vivo study of the inhibitory effects of Vaccinium myrtillus anthocyanosides on human platelet aggregation. Fitoterapia 1989;60:69-75.
  7. Bottecchia D. Preliminary report on the inhibitory effect of vaccinium myrtillus anthocyanosides on platelet aggregation and clot retraction. Fitoterapia 1987;48:3-8.
  8. Fdez, M., Zaragoza, F., and Alvarez, P. In vitro platelet aggregation effects of anthocyanosides of vaccinium myrtilus L. Anales de la Real Academia de Farmacia 1983;49:79-90.
  9. Biedermann L, Mwinyi J, Scharl M, Frei P, Zeitz J, Kullak-Ublick GA, et al. Bilberry ingestion improves disease activity in mild to moderate ulcerative colitis-an open pilot study. 2013 May;7(4):271-9. PubMed
  10. Hoggard N, Cruickshank M, Moar KM, Bestwick C, Holst J, Russell W, et al. A single supplement of a standardized bilberry (Vaccinium myrtillus L.) extract (36% wet weight anthocyanins) modifies glycaemic response in individuals with type 2 diabetes control
  11. Aichinger G, Pahlke G, Nagel LJ, Berger W, Marko D. Bilberry extract, its major phenolic compounds, and soy isoflavone genistein antagonize the cytostatic drug erlotinib in human epithelial cells. Food Funct 2016;7(8):3628-36.
  12. Prokop J, Lněničková K, Cibicek N, et al. Effect of bilberry extract (Vaccinium myrtillus L.) on drug-metabolizing enzymes in rats. Food Chem Toxicol 2019;129:382-90. PubMed
  13. Chan SW, Chu TTW, Choi SW, Benzie IFF, Tomlinson B. Impact of short-term bilberry supplementation on glycemic control, cardiovascular disease risk factors, and antioxidant status in Chinese patients with type 2 diabetes. Phytother Res 2021. Online ahead o PubMed
  14. Bøhn SK, Myhrstad MCW, Thoresen M, et al. Bilberry/red grape juice decreases plasma biomarkers of inflammation and tissue damage in aged men with subjective memory impairment -a randomized clinical trial. BMC Nutr 2021;7(1):75. PubMed

See these in context on the Bilberry 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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