Known interactions

2-Amino-2-Deoxyglucose, Abciximab Injection, Acanthopanax senticosus, Achillea, Achillea millefolium, Ackerkraut, African Pepper, Agathosma betulina, Aggrastat, Agrimonia, Agrimonia eupatoria, Agrimony, Agrylin, Alfalfa, Alhova, Allium, Allium sativum, Altamisa, Amachazuru, American Cranberry, Anagrelide, Angelica polymorpha, Angelica sinensis, Anthemis nobilis, Apricot Vine, Arandano, Ardeparin Sodium Injection--No longer available, Armoracia rusticana, Arnica, Arnica montana, Asian Ginseng, Aspirin and Carisoprodol, Aspirin, Caffeine and Dihydrocodeine, Awa, Barosma betulina, Basket Willow, Bee Bread, Bird Pepper, Bird's Foot, Black ginger, Bloodwort, Borage, Borago officinalis, Bridewort, Bucco, Buchu, Buffered Aspirin and Pravastatin, Bugloss, Buku, Cabbage Palm, Cacari, Caffeine, Aspirin and Dihydrocodeine, Camocamo, Camu-camu, Canton ginger, Capsicum, Capsicum annuum, Capsicum frutescens, Carica papaya, Carisoprodol Compound, Chamomile, Chili Pepper, Chinese Angelica, Chinese Ginseng, Chinese Sage, Chitosamine, Chondroitin, Chondroitin Sulfate, Chrysanthemum parthenium, Church Steeples, Ci Wu Jia, Cilostazol, Clopidogrel, Cochin ginger, Cochlearia armoracia, Cocklebur, Common Borage, Common Bugloss, Common ginger, Corona de Cristo, Coumadin, Coumadin Injection, Cow Clover, Crack Willow, Cranberry, Curcuma, Curcuma species, Daidzein, Dalteparin Injection, Danaparoid Injection, Danggui, Danshen, Devil's Bush, Devil's Claw, Devil's Leaf, Dihydrocodeine, Aspirin and Caffeine, Diosma, Dipyridamole, Dipyridamole Injection, Dong Quai, Dropwort, Eleuthero, Eleutherococcus senticosus, Enoxaparin Injection, Eptifibatide, Evening Primrose, Fan Palm, Featherfew, Fenugreek, Feuille de Luzerna, Fever Plant, Feverfew, Filipendula ulmaria, Flirtwort, Fragmin, Funffing, Gan Cao, Garden ginger, Garlic, Ge Gen, Genuine chamomile, German Chamomile, German Mustard, Gingembre, Ginger, Ginkgo, Ginkgo Biloba, Ginseng, Panax, Glucosamine, Glucosamine Hydrochloride, Glucosamine Sulfate, Glycine max, Glycine soja, Glycyrrhiza glabra, Goat's Pod, Granadilla, Grape Seed, Grape Seed Extract, Grapple Plant, Great Raifort, Greek Clover, Greek Hay, Green Arrow, Guavaberry, Guigai, Gynostemma, Gynostemma pentaphyllum, Harpagophytum procumbens, Heparin Injection, Herbe de Saint-Guillaume, Horse Chestnut, Horse Radish, Horseradish, Hu Lu Ba, Huang Ken, Hungarian chamomile, Imber, Indian Saffron, Innohep, Integrilin, Ipe Roxo, Ipes, Jamaican ginger, Jantoven, Japanese Arrowroot, Japanese Ginseng, Japanese Silver Apricot, Jiaogulan, Kava, Kava-Kava, Kawa, Kew, Kew Tree, Korean Ginseng, Kudzu, Lady of the Meadow, Lapacho, Leopard's Bane, Licorice, Liquorice, Liverwort, Lovenox, Lucerne, Maidenhair Tree, Matricaria chamomilla, Maypop, MEL, Meadow Clover, Meadowsweet, Medicago, Medicago sativa, Melatonin, Methi, Mexican Chillies, Milfoil, Miracle Grass, MLT, Mossberry, Mountain Radish, Mountain Snuff, Mountain Tobacco, Muscat, N-acetyl Glucosamine, N-acetyl-5-methoxytryptamine, Nettle, Nettle Tops, Ninjin, Normiflo - No longer available, Nosebleed Plant, OEP, Oenothera species, Orgaran, Oriental Ginseng, Ox's Tongue, Panax Ginseng, Panax schinseng, Papain, Paprika, Passiflora incarnata, Passion Flower, Passion Vine, Pau D'arco, Pepperrot, Persantine, Persantine Injection, Piper methysticum, Plavix, Pletal, Pravigard PAC, Pueraria, Pueraria lobata, Pueraria montana, Pueraria thunbergiana, Pulmonaria Officinalis, Purple Clover, Purple Medick, Pyrethrum parthenium, Queen of the Meadow, Radix Salvia, Red Clover, Red Cole, Red Ginseng, Red Pepper, Red Sage, Red Wine Extract, ReoPro, Roman Chamomile, Roman Nettle, Rumberry, Russian Root, Rustic Treacle, Sabal, Sabal serrulata, Salix, Salix alba, Salix fragilis, Salix purpurea, Salvia miltiorrhiza, Salvia Root, Saw Palmetto, Scrub Palm, Seng, Serenoa, Serenoa repens, Shigoka, Siberian Ginseng, Sodol Compound, Soma Compound, Southern Ginseng, Soy, Soya, Soybeans, Spirea, Spirea ulmaria, Starflower, Staunch Weed, Stickwort, Stinging Nettle, Stingnose, Stinking Rose, Sun Drop, Sweet Root, Synalgos-DC, Tabasco Pepper, Tabebuia species, Taheebo, Taiga, Tanacetum parthenium, Tang-Kuei, Ten Shen, Thorny Pepperbush, Thousand-Leaf, Ticlid, Ticlopidine, Tinzaparin, Tirofiban, Tonga, Touch-Me-Not, Trefoil, Trifolium pratense, Trigonella, Trigonella foenum-graecum, Trumpet Bush, Turmeric, Urtica species, Vaccinium species, Vegetable pepsin, Vitis pentaphyllum, Vitis vinifera, Warfarin, Warfarin injection, Water Lemon, White Willow, Wild Chamomile, Wild Clover, Wild Pepper, Wild Quinine, Wolf's Bane, Wolfbane, Wood Spider, Wound Wort, Xianxao, Yagona, Yarrow, Yarroway, Yege, Yinhsing, Zanzibar Pepper, Zingiber officinale.

Info about Winterlein

Scientific Name: Flaxseed

Other Names: Flaxseed oil, Graine de lin, Leinsamen, Linseed, Linseed oil, Lint bells, Linum, Winterlein

Who is this for?

Note: Only flax products that are packaged specifically for food or medicinal use should be taken by mouth. Flaxseed sold for planting and flaxseed oil sold for painting or other purposes are not suitable for human consumption. Products labeled as "linseed oil" should never be taken by mouth.

Today, one major use of flax is as a laxative. Because flax seeds are coated with mucilage, a natural gummy substance that does not dissolve in water, they form a thick, gooey mass when exposed to fluids. The body does not digest mucilage, so the resulting large soft mass moves through the intestines and also triggers intestinal muscle contractions. In addition, the mucilage forms a slick coating on the walls of the intestines. All of these effects help to prevent or relieve constipation. Flaxseed oil may also be taken by mouth for a mild laxative effect. Both flaxseed and flaxseed oil may also be used to treat other gastrointestinal complaints such as irritable bowel syndrome.

Historically, however, flaxseed has been used to treat a number of conditions including heart disease. In the last 20 years or so, interest in the possible effects of flax products on the heart has been renewed, somewhat. Research has been done to test the effectiveness of flaxseed and flaxseed oil in reducing high blood pressure and high cholesterol. Generally, in animal studies and small human studies, flaxseed produced modest-to-significant reductions in total cholesterol, triglycerides, and/or low-density lipoproteins (LDL), the “bad” type of cholesterol. In some studies, though, decreases were not significant or blood levels of high-density lipoproteins (HDL), the “good” type of cholesterol also decreased. Separate animal studies showed a small decrease in blood pressure. However, these results have not been confirmed in larger human studies.

Flaxseed was thought to possess some anti-estrogenic effects, which have been studied for possible protection against certain types of breast and prostate cancers. However, when these effects were tested in several laboratory studies and a few human studies, the results were inconclusive. In some of the studies, flaxseed products appeared to prevent or delay cancer, while in other research the incidence and/or progression of cancer seemed to be increased, suggesting that flaxseed may have estrogen-like effects. Other herbal products with estrogenic properties have been used by men to lessen benign prostate enlargement and by women to relieve menstrual cramps and symptoms of menopause. They may also prevent or treat osteoporosis. At least one study of laboratory animals has shown that flaxseed in the diet may reduce the amount of chromosome damage that may be caused by cancer, but not enough is known about the cause of chromosome damage or its prevention to recommend flaxseed for cancer prevention. Additional studies are underway to assess further the possible effects of flaxseed and flaxseed oil on breast and prostate cancers, osteoporosis, and menopausal symptoms.

More recently, flaxseed has been studied for its potential to prevent kidney damage in individuals who have an autoimmune condition known as systemic lupus erythematosus (SLE). Some evidence from animal studies and human case reports supports the use for SLE, but more studies are needed before flaxseed can be recommended for this use.

Flaxseed oil can be applied topically to soften dry skin. Also for topical use, a poultice can be made by mixing whole or crushed flaxseed with about three times as much hot water as the amount of flaxseed and then letting the mixture stand until it makes a thick gel. A soft cloth is then covered with the gel, possibly heated, and applied to an aching or injured area of skin surface.

When should I be careful taking it?

In studies of laboratory animals, flaxseed has shown both estrogen-like and anti-estrogenic effects. Although one small pilot study of breast-feeding women showed no adverse effects in infants whose breast-feeding mothers took flaxseed oil, pregnant and breast-feeding women are not advised to use flaxseed or flaxseed oil. Potentially, the unpredictable estrogenic or anti-estrogenic effects may affect developing fetuses and infants. In addition, the possible effects of flaxseed or flaxseed oil on young children have not been studied, so they are not recommended for children under 12 years of age.

Women with hormone-dependent conditions such as endometriosis, uterine fibroids, or cancers of the breast, ovaries, or uterus should not take flaxseed products due to possible estrogenic effects. Men with prostate cancer should also avoid taking flaxseed products.

Flaxseed can block the esophagus or parts of the intestinal tract. Therefore individuals who have had esophageal or intestinal blockages should not use flaxseed.


Flaxseed must be taken with adequate quantities of water (about 8 ounces of water or other liquid for each tablespoon of flaxseed) to prevent gastrointestinal blockages.

What side effects should I watch for?

If flaxseed or flaxseed oil is used in high doses or for prolonged periods of time, reduced potassium levels in the body may result. Low potassium levels can result in muscle weakness and potentially dangerous changes in heart rhythm.

Less Severe Side Effects

Side effects associated with taking flaxseed are gastrointestinal complaints such as diarrhea, gas, nausea, and stomach pain.Taking flaxseed oil by mouth may result in oily leakage from the digestive tract.

Allergic reactions have been reported by individuals who took flaxseed or flaxseed oil and by individuals who work in growing or processing flax plants.

What interactions should I watch for?

Prescription Drugs

In case studies, flaxseed oil has been reported to increase the time blood needs to clot. When it is taken with antiplatelet or anticoagulant drugs, the effect of the drug may be increased, resulting in uncontrolled bleeding.

  • Antiplatelets include Plavix and Ticlid
  • Anticoagulants include heparin and warfarin

When mixed with water or other fluids, flaxseed forms a sticky, slippery gel. In theory, taking flaxseed by mouth could block the absorption of other drugs that are taken at the same time. If you take flaxseed, do not take other drugs within 2 hours.

Non-prescription Drugs

Flaxseed and flaxseed oil can affect the ability of blood to clot after an injury. Aspirin can also delay clotting, so flax products should not be taken at the same time as aspirin.

Herbal Products

Theoretically, if flaxseed oil is used with other supplements that affect blood clotting, bleeding may occur. Some of the most common herbal products that might inhibit blood clotting are:

  • Danshen
  • Devil's Claw
  • Garlic
  • Ginger
  • Ginkgo
  • Ginseng
  • Horse Chestnut
  • Papain
  • Red Clover
  • Saw Palmetto

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?

Flax plants have been used by humans for at least 10,000 years. It is believed that flax is one of the first plants that early humans learned to grow for purposes other than food. Linen cloth was used to wrap Egyptian mummies and flax is mentioned prominently in the Bible as a source of both food and cloth. Thought to have originated in southern Europe, flax was once cultivated extensively in most parts of the world that have cool, damp climates. Presently, it is grown as a large-scale crop only in eastern Europe.

Flax grows an annual plant with small leaves surrounding strong stems. During most of the summer, light blue or lavender colored flowers bloom at the ends of the stems, which can reach up to 3 feet in height. At the end of the growing season, the seeds are harvested and the plants are left to dry in the fields. The dried flax stems are softened in water and then pounded to separate the fibers that can be woven into linen cloth. In the past, flax fibers were used to make paper and they are still used to strengthen some paper money. Linen is also used as artists' canvas and flaxseed oil is an essential ingredient in oil paints.

Flaxseeds provided early humans with a reliable food source. Flaxseeds are high in protein, they can be dried and saved for long periods, and they are easily transported. The oil that can be extracted from flaxseeds contains a high percentage of polyunsaturated fatty acids—particularly alpha-linolenic acid, which is essential for maintaining the integrity of cell membranes. In addition to their nutritional value, flaxseeds also produce oil that has been used in concrete, insulation, paint, soap, and waterproofing material. Even flaxseed residue left after the oil has been removed may be used as animal feed, commonly called flax cakes. Both flaxseeds and the oil from flaxseeds are used in medicine.

Dosage and Administration

Whole, crushed, or ground flaxseeds can be added to beverages or bakery. Also available are flaxseed powder-filled capsules. Flaxseed oil comes in soft capsules or as a liquid, which both must be protected from heat and light.

For use as a laxative, a common dose of whole or crushed flaxseed is one tablespoonful (approximately 15 grams) two or three times a day. Because flaxseed swells when it gets wet, taking it with enough water — approximately 8 ounces of water for each tablespoonful of flaxseed — is very important to prevent blockage in the esophagus, stomach, or intestines.

Alternatively, one to three tablespoons of flaxseed oil can be used per day as a laxative. Either the seed or the oil can be added to drinks or soft foods. Flaxseed can also be baked into breads, cookies, or muffins. Flaxseed oil can be used in salad dressing, but it should not be heated because heating destroys some of the active ingredients in it.

For high cholesterol, a daily dose of 40 to 50 grams (approximately three tablespoons) of flaxseed or one to three tablespoons of flaxseed oil is recommended.


Flaxseed and flaxseed oil are effective laxatives and they may also help to lower blood pressure and cholesterol levels.

Topically, flaxseed oil softens skin and a poultice of flaxseed soothes irritated skin.


Flaxseed's possible estrogenic/anti-estrogenic effects make it unsuitable for pregnant and breast-feeding women, small children, and individuals with hormone-dependent conditions such as endometriosis and cancers of the breast, ovaries, prostate, or uterus.Individuals who have or have had esophageal or intestinal blockages should avoid taking flaxseed due to the possibility of blockage.

Side Effects

High or prolonged use of flaxseed or flaxseed oil may lead to possibly dangerously low levels of potassium in the body. Other side effects that have been associated with using flaxseed or flaxseed oil by mouth include relatively minor gastrointestinal complaints.


Flaxseed products may increase the time that blood takes to clot, therefore they may increase the effects of drugs or herbal products that also delay blood clotting. Potentially, flaxseed taken by mouth may block the effectiveness of other drugs that are also taken by mouth. Flaxseed should be taken at least 2 hours before or 2 hours after other drugs are taken.

Last Revised September 9, 2004


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(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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