Known interactions

2-Amino-2-Deoxyglucose, Acanthopanax senticosus, Acarbose, Acetohexamide, Ackerkraut, Actoplus Met, Actos, Agrimonia, Agrimonia eupatoria, Agrimony, Alant, Alfalfa, Alhova, Allium, Allium sativum, Aloe barbadensis, Aloe species, Aloe vera, Amaryl, American Ginseng, Amorphophallus konjac, Anchi, Apidra, Asian Ginseng, Avandamet, Avandia, Azucacaa, Baikal Scullcap, Baikal Skullcap Root, Bal, Barley, Barley Grass, Basket Willow, Bdellium, Bird's Foot, Black ginger, Black Psyllium, Blond Psyllium, Blowball, Bol, Bramhi, Burn Plant, Canadian Ginseng, Canker Wort, Canton ginger, Cape Aloe, Capim Doce, Centella asiatica, Chinese Ginseng, Chitosamine, Chlorpropamide, Chroma-Pak injection, Chromic Chloride injection, Chromium, Chromium 3, Chromium Acetate, Chromium Chloride, Chromium chloride injection, Chromium injection, Chromium Picolinate, Church Steeples, Ci Wu Jia, Co Q 10, Cochin ginger, Cocklebur, Coenzyme Q-10, Commiphora molmol, Commiphora myrrha, Common ginger, Crack Willow, Curcuma, Curcuma species, Daidzein, Damiana, Dandelion, Devil's Bush, Devil's Claw, Devil's Leaf, Devil's Tongue, Diabeta, Diabinese, Dymelor, Elecampane, Elephant-foot Yam, Eleuthero, Eleutherococcus senticosus, Elf Dock, Elfwort, Enebro, Erva Doce, Eucalyptus, Fenugreek, Feuille de Luzerna, Five Fingers, Flea Seed, Fortamet, Funffing, Garden ginger, Garlic, Ge Gen, Genevrier, Ginepro, Gingembre, Ginger, Ginkgo, Ginkgo Biloba, Ginseng, American, Ginseng, Panax, Glimepiride, Glipizide, Glipizide and Metformin, Glipizide Extended-Release, Glucomannan, Glucophage, Glucophage XR, Glucosamine, Glucosamine Hydrochloride, Glucosamine Sulfate, Glucotrol, Glucotrol XL, Glucovance, Glyburide, Glyburide and Metformin, Glynase, Glyset, Gotu Kola, Grapple Plant, Greek Clover, Greek Hay, Guggal Resin, Guigai, Gum Myrrh, Gurmar, Gymnema sylvestre, Harpagophytum procumbens, Heerabol, Herba de la pastora, Herbe de Saint-Guillaume, Hordeum vulgare, Horse-elder, Horseheal, Hu Lu Ba, Huang Qin, Humalog, Humalog Mix 75/25, Humulin, Humulin 50/50, Humulin 70/30, Hwanggum, Hydrocotyle asiatica, Iletin II, Iletin II Mixed, Imber, Indian Pennywort, Indian Saffron, Insulin - Mixed, Insulin glulisine, Insulin injection, Insulin Lispro, Inula helenium, Irish Daisy, Isphagula, Jamaican ginger, Japanese Arrowroot, Japanese Ginseng, Japanese Silver Apricot, Juniper, Juniperus communis, Kaa Jhee, Kew Tree, Konjac, Konjac Mannan, Konnyaku, Korean Ginseng, Kudzu, Kuli, Leotodon taraxacum, Lion's Tooth, Liverwort, Lucerne, Mai Ya, Maidenhair Tree, Marsh Penny, MEL, Medicago, Medicago sativa, Melatonin, Merasingi, Metaglip, Metformin, Metformin Extended-Release, Metformin Oral Solution, Methi, Mexican damiana, Micronase, Miglitol, Mitoquinone, Mizibcoc, MLT, Mo Yao, Myrrh, N-acetyl Glucosamine, N-acetyl-5-methoxytryptamine, Nettle, Nettle Tops, Ninjin, Nopal, North American Ginseng, NovoLog Mix, Novolin, Novolin 70/30, Ogon, Old woman's broom, Oleae europaea, Oleae folium, Oleum olivae, Olive Leaf, Olive Oil, Olivier, Opopanax, Opuntia species, Oriental Ginseng, Orinase, Panax Ginseng, Panax quinquefolius, Panax schinseng, Pearl Barley, Pioglitazone, Pioglitazone and Metformin, Plantago species, Plantain Seed, Prandin, Precose, Prickly Pear Cactus, Psyllium Seed, Pueraria, Pueraria lobata, Pueraria montana, Pueraria thunbergiana, Puffball, Purple Medick, Pushkarmoola, Q 10, Red Berry, Red Ginseng, Ren Shen, Repaglinide, Riomet, Roman Nettle, Rosiglitazone, Rosiglitazone and Metformin, Russian Root, Rustic Treacle, Salix, Salix alba, Salix fragilis, Salix purpurea, Scabwort, Scotch Barley, Scute, Scutellaria baicalensis, Seng, Shigoka, Siberian Ginseng, Snake Plant, Stevia, Stevia eupatorium, Stevia rebaudiana, Stickwort, Stinging Nettle, Stinking Rose, Sweet Herb, Sweet Oil, Sweetleaf, Taiga, Taraxacum officinale, Thorny Pepperbush, Tolazamide, Tolbutamide, Tolinase, Touch-Me-Not, Trigonella, Trigonella foenum-graecum, Trivalent Chromium, Turmeric, Turnera diffusa, Ubidecarenone, Ubiquinone, Urtica species, Velosulin, Velvet Dock, Vitamin Q, Wacholder, White Willow, Wild Endive, Wild Pepper, Wild Sunflower, Wogon, Wood Spider, Yege, Yellow Starwort, Yerba Dulce, Yinhsing, Zingiber officinale.

Information about Wineberry

Scientific Name: Bilberry

Other Names: Airelle, Dyeberry, European Blueberry, Huckleberry, Vaccinium myrtillus, Whortleberry, Wineberry

Who is this for?

Currently, bilberry is probably best known for treating eye conditions. It has been shown in clinical studies to decrease some of the retinal damage caused by diabetes or high blood pressure in at least two ways. First, it contains chemicals known as anthocyanosides, which may increase retinal pigments (coloring agents) that allow the eye to tolerate light. Additionally, bilberry may help to make the walls of blood vessels in the eyes stronger by increasing collagen linkages. As one result, retinopathy (the gradual break down of the retina in the eyes) may be slowed. Individuals with hardening of the arteries, diabetes, high blood pressure, or other conditions that increase the likelihood for damage to the small blood vessels in the eyes are more likely to have serious vision problems as a result of blood vessel damage. Note that bilberry is taken by mouth to treat eye problems. It is not used as an eye drop.

Oral bilberry preparations are also used to prevent and treat a condition known as chronic venous insufficiency, which occurs when valves in the veins that carry blood back to the heart are weak or damaged. Blood may collect in the veins of the legs and lead to varicose veins, spider veins, or sores on the legs. More serious results can include blood clots in the legs. Because bilberry may strengthen the walls of all blood vessels in the body, taking it may also relieve hemorrhoids.

It is known that bilberries contain tannins, although the actual tannin content may fluctuate between as little as 1.5% and as much as 10%. Drying bilberry fruits concentrates the tannins, so dried bilberries generally contain a higher percentage than fresh bilberries. In the past, dried bilberries have been used to treat diarrhea because the tannins act as an astringent to the gastrointestinal tract. An astringent shrinks and tightens the top layers of skin or mucous membranes, thereby reducing secretions, relieving irritation, and improving tissue firmness. Due to the same astringent effect, tea brewed from dried bilberry fruits has also been used to soothe a sore throat or sore mouth tissue.

In folk medicine, bilberry leaf has been used to treat a number of conditions including diabetes. Limited evidence from a few animal studies shows that it may have a decreasing effect on blood sugar. Additionally, in at least one study, an extract of bilberry leaves may also have lowered cholesterol levels in laboratory animals. Other laboratory and animal studies have tested potential anticancer effects of bilberry. In a laboratory study, bilberry stopped the growth of both leukemia and colon cancer cells. While preliminary results suggest that anthocyanosides obtained from bilberries may also block the effects of an enzyme and other chemicals that promote tumor growth, much more study is needed. To date, no human clinical studies have confirmed any of these results from bilberry.

When should I be careful taking it?

Eating bilberry fruit seems to be safe during pregnancy and while breast-feeding, but no studies have been done to test the safety of supplemental doses of bilberry fruit or bilberry leaf products. Until more is known, supplemental bilberry is best avoided by pregnant and breast-feeding women.

Because bilberry may have a lowering effect on blood sugar, bilberry may increase the effectiveness of medications used for the treatment of diabetes. If you are taking medications for diabetes, talk to your doctor or pharmacist before using supplementary bilberry.

What side effects should I watch for?

Although no reports of major side effects from bilberry were found in the literature, other oral preparations that are high in tannin content have been associated with kidney or liver damage. Individuals with kidney or liver conditions should not take bilberry products.

A case study of several people who regularly used large amounts of an oral product containing high levels of tannins for many years, found they had a higher incidence of tongue and lip cancer than expected. Cancers of the nose and esophagus may also be more likely in people who use large amounts of tannin-containing products for long amounts of time.

What interactions should I watch for?

Prescription Drugs

The possible blood sugar-lowering effects of bilberry leaf may interfere with insulin and oral drugs for diabetes, such as:

  • Actos
  • Amaryl
  • Avandia
  • glipizide (Glucotrol XL)
  • glyburide (Glynase)
  • Glyset
  • metformin (Glucophage)
  • Prandin
  • Precose

Herbal Products

Because bilberry leaf may decrease blood sugar levels, taking it with other blood sugar-lowering herbal products may result in hypoglycemia — blood sugar that is too low. Herbals that may reduce blood sugar include:

  • Eleuthero
  • Fenugreek
  • Ginger (in high amounts)
  • Kudzu
  • Panax ginseng


Although no interactions have been reported between bilberry and foods, the tannins in bilberry may interfere with the absorption of minerals such as calcium, iron, and magnesium from foods. A dietary deficiency of these minerals is very rare in the United States, but it might be possible if large amounts of bilberry are used.

No other interactions have been reported between bilberry and prescription drugs, non-prescription drugs, other herbal supplements, or foods. However, because few reliable studies of bilberry have been conducted, its possible interactions with drugs, foods, and other dietary supplements are not understood completely. Other oral products that contain tannins have interfered with the way the body uses certain drugs. Be sure that your doctor and pharmacist are aware of all the prescription and non-prescription medicines you take before you begin to use bilberry or any other herbal supplement.

Some interactions between herbal products and medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals.

Should I take it?

Closely related to blueberries, bilberries are believed to be native to Northeastern Europe. Although they are cultivated in some countries of Eastern Europe, most bilberries grow wild in damp woodlands and marsh edges. In Britain and Europe, bilberry is also often used in landscaping. A small perennial bush, bilberry bears white or pinkish flowers late in the spring. The leaves are quite attractive — during the growing season they are a light green or green-yellow that becomes a reddish color in the autumn. Both the flowers and the leaves are waxy in appearance. Numerous wrinkled, dark blue or black berries that resemble blueberries in size and shape ripen in the autumn.

Like other berries, bilberry fruits are harvested and used for cooking, baking, and making jams. They have a slightly sour taste more similar to cranberries than blueberries. In earlier times, bilberries were added to wine to give it color. They were also used to prevent scurvy, a condition caused by vitamin C deficiency. Both the fruits and, less frequently, the leaves of bilberry are used in medicine. Ripe bilberries are collected and dried; bilberry leaves are harvested and dried before they begin to color in the fall.

Dosage and Administration

Bilberry is available in commercial oral dosage forms such as capsules, extracts, and tablets. It is often sold in combination with other herbals such as eyebright or supplements such as beta-carotene that also may enhance vision. Each of these products has various strengths and different recommendations for dosing. If you decide to use one of them, follow the directions on the package that you buy.

A tea may be made from either dried bilberries or dried bilberry leaves. No limits are suggested for the maximum amount of tea per day, but continual use for more than a few days at a time is discouraged because of the tannin content.

  • To make bilberry fruit tea about 2 teaspoons of dried bilberries should be allowed to soften for several minutes or longer in about 5 ounces of cold water. The water should then be heated but not boiled for about 10 minutes. The bilberries should be removed before drinking the tea, but they may be eaten, if desired.
  • For bilberry leaf tea, soak about 2 teaspoons of the chopped dried leaf in about 5 ounces of boiling water for about 10 minutes, strain out the solid particles, and drink the tea.


Bilberries may be taken by mouth to treat retinopathy and other conditions, such as chronic venous insufficiency and hemorrhoids, that are associated with the deterioration of small blood vessels. They may also help to relieve diarrhea and sore throats. Leaves from the bilberry bush may also have some medicinal effects, but they have not been studied as much as the possible effects of the berries.


Bilberry contains varying amounts of chemicals known as tannins, which have been associated with kidney or liver damage. While eating small amounts of bilberries as part of the diet appears to be safe, consuming large amounts or continually taking supplemental bilberry should be avoided by pregnant women and individuals with diabetes.

Side Effects

Other oral products that contain high percentages of tannins may contribute to esophageal or mouth cancer. Kidney and liver damage may also result from continued use or high doses of oral products with high tannin contents.


Bilberry may interfere with the effectiveness of insulin, oral drugs for diabetes, and herbal products that affect blood sugar levels. It may also block the absorption of drugs and nutrients.


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Katsube N, Iwashita K, Tsushida T, Yamaki K, Kobori M. Induction of apoptosis in cancer cells by Bilberry (Vaccinium myrtillus) and the anthocyanins. Journal of Agricultural and Food Chemistry. 2003;51(1):68-75.

Kemper KJ. Bilberry (Vaccinium myrtillus). The Longwood Herbal Task Force. Revised September 9, 1999. Available at: Accessed: November 3, 2003.

Levy Y, Glovinsky Y. The effect of anthocyanosides on night vision. Eye. 1998;12:967-969.

Lietti A, Cristoni A, Picci M. Studies on Vaccinium myrtillus anthocyanosides. I. Vasoprotective and antiinflammatory activity. Arzneimittelforschung. 1976;26:829-832.

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Muth ER, Laurent JM, Jasper P. The effect of bilberry nutritional supplementation on night visual acuity and contrast sensitivity. Alternative Medicine Review. 2000;5(2):164-173.

Roy S, Khanna S, Alessio HM, et al. Anti-angiogenic property of edible berries. Free Radical Research. 2002;36(9):1023-1031.

Scharrer A, Ober M. Anthocyanosides in the treatment of retinopathies. [Article in German] Kiln Monastbl Augenheilkd. 1981;178(5):386-389.

Sparrow JR, Vollmer-Snarr HR, Zhou J, et al. A2E-epoxides damage DNA in retinal pigment epithelial cells. Vitamin E and other antioxidants inhibit A2E-epoxide formation. Journal of Biological Chemistry. 2003;278(20):18207-18213.

Talavera S, Felgines C, Texier O, Besson C, Lamaison JL, Remesy C. Anthocyanins are efficiently absorbed from the stomach in anesthetized rats. Journal of Nutrition. 2003;133(12):4178-4182.

Last Revised February 17, 2004

(Note: The above information is not intended to replace the advice of your physician, pharmacist, or other healthcare professional. It is not meant to indicate that the use of the product is safe, appropriate, or effective for you.)

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