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Dietary supplement

Extra Strength Bilberry Leaf 4:1 Extract Powder Ingredients & Drug Interactions

by TerraVita Premium Collection

Extra Strength Bilberry Leaf 4:1 Extract Powder label
See full label image
Powder 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 Extra Strength Bilberry Leaf 4:1 Extract Powder 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

Extra Strength Bilberry Leaf 4:1 Extract Powder is a dietary supplement by TerraVita Premium Collection with 1 active ingredient. 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 Leaf Extract, Powder. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Extra Strength Bilberry Leaf 4:1 Extract Powder by TerraVita Premium Collection

Ask about any prescription or over-the-counter medication and we check it for interactions with Extra Strength Bilberry Leaf 4:1 Extract Powder by TerraVita Premium Collection — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Extra Strength Bilberry Leaf 4:1 Extract Powder by TerraVita Premium Collection

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 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: bilberry leaf extract in a 4:1 concentrated powder form. Bilberry has been used traditionally to support eye and circulatory health, though modern evidence for many of these claims remains limited.

There are no inactive ingredients listed for this product.

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: Eye and vision health support.
  • We looked for evidence on: Age-related macular degeneration (AMD), Asthenopia (eye strain), Cataracts, Diabetic retinopathy, Dry eye, Glaucoma — 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 effectiveness is mixed and incomplete. For night vision, bilberry is rated possibly ineffective — meaning current data doesn't support its use for that purpose.

For age-related cognitive decline, age-related macular degeneration, atherosclerosis, high cholesterol, and chronic venous insufficiency, we don't hold enough reliable evidence to rate whether it works or not. If you're considering this product for a specific condition, your doctor or pharmacist can help you weigh what limited evidence exists against your individual needs.

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 itself is generally well tolerated as food, but the supplement form — especially concentrated extracts like this one — has limited long-term safety data. The safety notes we have advise caution with concentrated supplements and higher doses.

Most people who take bilberry experience no problems, though some report dark-colored stools, gas, and mild stomach discomfort. In one small study, about a third of people drinking concentrated bilberry juice reported flatulence, and roughly 13% reported temporary digestive upset.

You may also notice your stools, tongue, or even teeth temporarily darkening — this is harmless staining from the pigments and typically goes away once you stop taking it.

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 taking this product, check with your doctor or pharmacist if you take any blood thinners or antiplatelet drugs (like warfarin, aspirin, or clopidogrel) — bilberry may raise bleeding risk. Also flag diabetes medications and erlotinib (Tarceva), as bilberry may lower blood sugar further or reduce the cancer drug's effectiveness.

Let them know about any other medications you're on, since bilberry may interact with drugs processed by a specific liver enzyme.

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.

This bilberry extract carries real interaction risks with blood thinners, diabetes drugs, and certain cancer therapies, so it's not a casual add-on if you take prescription medication. Even if you don't, the evidence for what it actually does is thin.

Talk with your doctor or pharmacist before starting — they can tell you whether it makes sense for your health and whether it's safe alongside what you're already taking.

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

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jun 22, 2023.

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 Extra Strength Bilberry Leaf 4:1 Extract Powder, straight from the product label.

Brand TerraVita Premium Collection
Barcode (UPC) 064435112479
Net contents 1 Ounce(s)
Market status On market
Date entered into DSLD Jun 22, 2023
DSLD ID 290478
Product type Botanical
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) 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 Extra Strength Bilberry Leaf 4:1 Extract Powder by TerraVita Premium Collection, 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:
0.25 Teaspoon(s)
Maximum serving Sizes:
0.25 Teaspoon(s)
Servings per container
28
UPC/BARCODE
064435112479
IngredientAmount% DV
Bilberry Leaf Extract, Powder1000 mg--

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

A Dietary Supplement

Brand IP Statement(s)

Copyright 2004 TerraVita - Distributed by ZooScape LLC, All Rights Reserved.

Suggested/Recommended/Usage/Directions

Directions Stir 1/4 of a teaspoon into a glass of water and consume 3 times daily, with meals.

General Statements

TerraVita is an exclusive line of premium natural products that use the finest, purest and most potent ingredients in the world. TerraVita's hallmarks are the highest possible standards of purity, potency, stability and freshness. All products are prepared with the greatest quality control, from raw materials through the entire manufacturing process, right up to the moment your product is sealed for freshness and shipped to you.

Please recycle!

FDA Disclaimer Statement

Statements not evaluated by FDA. Product not intended to diagnose, treat, cure, or prevent any disease.

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

See for yourself

Extra Strength Bilberry Leaf 4:1 Extract Powder by TerraVita Premium Collection label

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

Extra Strength Bilberry Leaf 4:1 Extract Powder 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 Extra Strength Bilberry Leaf 4:1 Extract Powder by TerraVita Premium Collection

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size0.25 Teaspoon(s) Dosage formPowder Servings per container28 Amounts shown are per serving.

Bilberry Leaf Extract, Powder

Interacts with
275 drugs
1000 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 Leaf Extract, Powder monograph & interactions
Interaction report

Extra Strength Bilberry Leaf 4:1 Extract Powder by TerraVita Premium Collection Drug Interactions

Want to check YOUR meds against Extra Strength Bilberry Leaf 4:1 Extract Powder?

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 Leaf Extract, Powder 275

Individual Drug Interactions

The ingredients in Extra Strength Bilberry Leaf 4:1 Extract Powder interact with 275 drugs. Click any drug to see the details.

1 of the 1 ingredient in Extra Strength Bilberry Leaf 4:1 Extract Powder interact with drugs. Each result below shows which ingredient is responsible. Bilberry Leaf Extract, Powder

Each ingredient & the kinds of drugs it affects

For each ingredient in Extra Strength Bilberry Leaf 4:1 Extract Powder 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 Leaf Extract, Powder4 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 Leaf Extract, Powder full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Extra Strength Bilberry Leaf 4:1 Extract Powder, from the product label.

TerraVita Premium Collection

See all TerraVita Premium Collection products
Name
TerraVita Fine Whole Herbs
City
Brampton
State
Ontario
Pharmacist Counseling Corner

Extra Strength Bilberry Leaf 4:1 Extract Powder by TerraVita Premium Collection: Common Questions

Does Extra Strength Bilberry Leaf 4:1 Extract Powder by TerraVita Premium Collection interact with any medications?
Yes. Based on its ingredients, Extra Strength Bilberry Leaf 4:1 Extract Powder 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?
Extra Strength Bilberry Leaf 4:1 Extract Powder contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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.
Is bilberry safe to take during pregnancy or while breastfeeding?
Bilberry is rated likely safe in pregnancy and lactation. However, the safety data for concentrated supplement extracts is limited, so talk with your doctor or midwife before starting this product if you're pregnant or nursing — they can advise based on your individual situation.
What are the most common side effects?
Most people tolerate bilberry well. The most common effects are dark-colored or greenish stools, gas, and mild stomach discomfort. Your tongue, teeth, or stools may temporarily turn dark blue or black — this is harmless staining from the natural pigments and goes away once you stop.
Does bilberry really help with vision or memory?
For night vision, the evidence suggests it doesn't work. For age-related cognitive decline and other uses like macular degeneration, we don't have enough reliable data to say whether it helps or not. If you're hoping it will improve a specific health issue, ask your doctor what the science actually shows.
Can I take this if I'm on a blood thinner like warfarin?
Bilberry may increase your bleeding risk when combined with blood thinners or antiplatelet drugs. You shouldn't start this product without checking with your doctor or pharmacist first — they need to know about both medications and may monitor you more closely or advise against it.
What's the 4:1 extract ratio mean?
A 4:1 extract means the manufacturer concentrated the bilberry leaf by processing it so that one unit of powder is equivalent to four units of the original leaf material. This makes it stronger per serving than whole leaf powder, which is why concentrated extracts carry more caution around long-term safety.
Can I take this with my diabetes medication?
Bilberry may lower your blood sugar on its own, so taking it alongside diabetes drugs could raise your risk of low blood sugar (hypoglycemia). Talk with your doctor before starting — they may want to monitor your blood sugar more closely or adjust your medication.

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.

Extra Strength Bilberry Leaf 4:1 Extract Powder label
Go deeper

The Full Monographs Behind Extra Strength Bilberry Leaf 4:1 Extract Powder’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

Extra Strength Bilberry Leaf 4:1 Extract Powder'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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