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Red clover


What is it?

Red clover is a plant. The flower tops are used to make medicine.

Red clover is used for many conditions, but so far, there isn’t enough scientific evidence to determine whether it is effective for any of them. It doesn’t seem to work, though, for lowering cholesterol or controlling hot flashes in women.

Red clover is used for cancer prevention, indigestion, high cholesterol, whooping cough, cough, asthma, bronchitis, and sexually transmitted diseases (STDs).

Some women use red clover for symptoms of menopause such as hot flashes; for breast pain or tenderness (mastalgia); and for premenstrual syndrome (PMS).

Red clover is applied to the skin for skin cancer, skin sores, burns, and chronic skin diseases including eczema and psoriasis.

In foods and beverages, the solid extract of red clover is used as a flavoring ingredient.

Red clover contains hormone-like chemicals called isoflavones that seem to cause reproductive problems in certain animals. Experts think a diet high in isoflavones may have been responsible for reports of reproductive failure and liver disease in cheetahs living in zoos. In large quantities, red clover can cause sterility in livestock.

How effective is it?

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for RED CLOVER are as follows:

Possibly ineffective for...

  • High cholesterol in women. Research shows that taking red clover extracts by mouth for 3 months to a year does not seem reduce “bad” cholesterol or increase “good” cholesterol in women who have moderately elevated cholesterol levels.
  • Prevention of weak bones (osteoporosis) in women. Research shows that taking a red clover extract for a year does not seem to increase bone strength in women.

Insufficient evidence to rate effectiveness for...

  • Prostate gland symptoms (such as increased nighttime urination) in men. Research suggests that red clover supplements might improve symptoms of benign prostatic hyperplasia (BPH). It seems to decrease nighttime urination and improve the quality of life in men with BPH. But, red clover doesn’t seem to affect urine flow rate, prostatic-specific antigen (PSA) values, or prostate size.
  • Preventing cancer of the lining of the uterus (endometrial cancer). Research to date suggests that taking red clover supplements doesn’t seem to help prevent endometrial cancer.
  • Cyclical breast pain. There is some evidence that red clover might relieve cyclic breast pain and tenderness.
  • Menopause symptoms. There are contradictory research findings about the effects of red clover on symptoms of menopause. Most research shows that taking red clover by mouth for up to a year does not reduce symptoms such as hot flashes or night sweats. Some research shows that a specific red clover product (Promensil, Novogen) might reduce severity of hot flashes, but doesn’t reduce frequency of hot flashes.
    Other research shows that a different form of red clover (MF11RCE, Melbrosin International) might improve symptoms of menopause-related anxiety and depression.
  • Indigestion.
  • Lung problems (cough, bronchitis, asthma).
  • Sexually transmitted diseases (STDs).
  • Premenstrual syndrome (PMS).
  • Skin problems (cancerous growths, burns, eczema, psoriasis).
  • Other conditions.
More evidence is needed to rate red clover for these uses.

How does it work?

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Red clover contains “isoflavones” which are changed in the body to “phytoestrogens” that are similar to the hormone estrogen.

Are there safety concerns?

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Red clover is LIKELY SAFE for most people when used in the amounts found in food. It is POSSIBLY SAFE when used in medicinal amounts.

Red clover can cause rash-like reactions, muscle ache, headache, nausea, and vaginal bleeding (spotting) in some women.

There isn’t enough information to rate the safety of red clover when applied to the skin.

Special precautions & warnings:

Pregnancy and breast-feeding: Red clover is LIKELY SAFE when taken by mouth in amounts commonly found in food. But it is LIKELY UNSAFE when taken by mouth in medicinal amounts. Red clover acts like estrogen and might disturb important hormone balances during pregnancy or breast-feeding. Don’t use it.

Not enough is known about the safety of red clover when applied to the skin during pregnancy or breast-feeding. Stay on the safe side and don’t use it.

Bleeding disorders: Red clover might increase the chance of bleeding. Avoid large amounts and use with caution.

Hormone-sensitive conditions such as breast cancer, uterine cancer, ovarian cancer, endometriosis, or uterine fibroids: Red clover might act like estrogen. If you have any condition that might be made worse by exposure to estrogen, don’t use red clover.

Protein S deficiency: People with protein S deficiency have an increased risk of forming blood clots. There is some concern that red clover might increase the risk of clot formation in these people because it has some of the effects of estrogen. Don’t use red clover if you have protein S deficiency.

Surgery: Red clover might slow blood clotting. It might increase the chance of extra bleeding during and after surgery. Stop taking red clover at least 2 weeks before a scheduled surgery.

Are there interactions with medications?

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Moderate

Be cautious with this combination.

Birth control pills (Contraceptive drugs)
Some birth control pills contain estrogen. Red clover might have some of the same effects as estrogen. But red clover isn't as strong as the estrogen in birth control pills. Taking red clover along with birth control pills might decrease the effectiveness of birth control pills. If you take birth control pills along with red clover, use an additional form of birth control such as a condom.

Some birth control pills include ethinyl estradiol and levonorgestrel (Triphasil), ethinyl estradiol and norethindrone (Ortho-Novum 1/35, Ortho-Novum 7/7/7), and others.

Estrogens
Large amounts of red clover might have some of the same effects as estrogen. But red clover isn't as strong as estrogen pills. Taking red clover along with estrogen pills might decrease the effects of estrogen pills.

Some estrogen pills include conjugated equine estrogens (Premarin), ethinyl estradiol, estradiol, and others.

Medications changed by the liver (Cytochrome P450 1A2 (CYP1A2) substrates)
Some medications are changed and broken down by the liver. Red clover might decrease how quickly the liver breaks down some medications. Taking red clover along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking red clover, talk to your healthcare provider if you take any medications that are changed by the liver.

Some medications that are changed by the liver include amitriptyline (Elavil), haloperidol (Haldol), ondansetron (Zofran), propranolol (Inderal), theophylline (Theo-Dur, others), verapamil (Calan, Isoptin, others), and others.

Medications changed by the liver (Cytochrome P450 2C19 (CYP2C19) substrates)
Some medications are changed and broken down by the liver. Red clover might decrease how quickly the liver breaks down some medications. Taking red clover along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking red clover, talk to your healthcare provider if you take any medications that are changed by the liver.

Some medications that are changed by the liver include omeprazole (Prilosec), lansoprazole (Prevacid), and pantoprazole (Protonix); diazepam (Valium); carisoprodol (Soma); nelfinavir (Viracept); and others.

Medications changed by the liver (Cytochrome P450 2C9 (CYP2C9) substrates)
Some medications are changed and broken down by the liver. Red clover might decrease how quickly the liver breaks down some medications. Taking red clover along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking red clover, talk to your healthcare provider if you take any medications that are changed by the liver.

Some medications that are changed by the liver include diclofenac (Cataflam, Voltaren), ibuprofen (Motrin), meloxicam (Mobic), and piroxicam (Feldene); celecoxib (Celebrex); amitriptyline (Elavil); warfarin (Coumadin); glipizide (Glucotrol); losartan (Cozaar); and others.

Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates)
Some medications are changed and broken down by the liver. Red clover might decrease how quickly the liver breaks down some medications. Taking red clover along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking red clover, talk to your healthcare provider if you are taking any medications that are changed by the liver.

Some medications changed by the liver include lovastatin (Mevacor), ketoconazole (Nizoral), itraconazole (Sporanox), fexofenadine (Allegra), triazolam (Halcion), and many others.

Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
Large amounts of red clover might slow blood clotting. Taking red clover along with medications that also slow clotting might increase the chances of bruising and bleeding.

Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.

Tamoxifen (Nolvadex)
Some types of cancer are affected by hormones in the body. Estrogen-sensitive cancers are cancers that are affected by estrogen levels in the body. Tamoxifen (Nolvadex) is used to help treat and prevent these types of cancer. Red clover seems to also affect estrogen levels in the body. By affecting estrogen in the body, red clover might decrease the effectiveness of tamoxifen (Nolvadex). Do not take red clover if you are taking tamoxifen (Nolvadex).

Are there interactions with herbs and supplements?

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Herbs and supplements that might slow blood clotting
Red clover might slow blood clotting. Using red clover along with other herbs and supplements that can slow clotting could increase the chances of bleeding and bruising in some people. Some of these herbs include angelica, clove, danshen, garlic, ginger, ginkgo, Panax ginseng, horse chestnut, turmeric, and others.

Herbs with estrogenic activity
Large amounts of red clover might have some of the same effects as estrogen. Using red clover along with other herbs that also have some of the effects of estrogen might raise or lower the estrogen-like activity of these other herbs. These herbs include alfalfa, black cohosh, chasteberry, flaxseed, hops, ipriflavone, kudzu, licorice, and soy.

Are there interactions with foods?

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There are no known interactions with foods.

What dose is used?

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The appropriate dose of red clover depends on several factors such as the user’s age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for red clover. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Other names

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Beebread, Clovone, Cow Clover, Daidzein, Genistein, Isoflavone, Meadow Clover, Miel des Prés, Phytoestrogen, Purple Clover, Trebol Rojo, Trèfle Commun, Trèfle des Prés, Trèfle Pourpre, Trèfle Rouge, Trèfle Rougeâtre, Trèfle Violet, Trefoil, Trifolium, Trifolium pratense, Wild Clover.

Methodology

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To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.methodology (http://www.nlm.nih.gov/medlineplus/druginfo/natural/methodology.html).

References

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To see all references for the Red clover page, please go to http://www.nlm.nih.gov/medlineplus/druginfo/natural/308.html.

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Last reviewed - 07/18/2011




Page last updated: 01 July 2014