This plant grows in Europe and North America. The flowering tops are used in botanical medicine. Another plant, white clover, grows in similar areas. Both have white arrow-shaped patterns on their leaves.
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3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
80 mg of isoflavones daily
Red clover is an herb with weak estrogen-like actions similar to soy. In one study, isoflavones from red clover reduced the frequency of hot flashes in postmenopausal women.
A variety of herbs with weak estrogen-like actions similar to the effects of soy have traditionally been used for women with menopausal symptoms.2 These herbs include licorice, alfalfa, and red clover. In a double-blind trial, a formula containing tinctures of licorice, burdock, dong quai, wild yam, and motherwort (30 drops three times daily) was found to reduce symptoms of menopause.3 No effects on hormone levels were detected in this study. In a separate double-blind trial, supplementation with dong quai (4.5 grams three times daily in capsules) had no effect on menopausal symptoms or hormone levels.4 A double-blind trial using a standardized extract of subterranean clover (Trifolium subterraneum), a relative of red clover, containing 40 mg isoflavones per tablet did not impact symptoms of menopause, such as hot flashes, though it did improve function of the arteries.5 An extract of red clover, providing 82 mg of isoflavones per day, also was ineffective in a 12-week double-blind study.6 In another double-blind study, however, administration of 80 mg of isoflavones per day from red clover reduced the frequency of hot flashes in postmenopausal women. The benefit was noticeable after 4 weeks of treatment and became more pronounced after a total of 12 weeks.7 An extract of red clover also decreased symptoms of anxiety and depression in postmenopausal women in a double-blind study. The extract provided 80 mg of isoflavones per day and was taken for 90 days.8
Take an extract supplying 26 mg of biochanin A, 16 mg of formononetin, 1 mg of genistein, and 0.5 mg of daidzein per day
In one study, supplementing with isoflavones from red clover reduced the amount of bone loss from the spine by 45%, compared with a placebo.
In a double-blind study, supplementation with isoflavones from red clover for one year reduced the amount of bone loss from the spine by 45%, compared with a placebo.9 The supplement used provided daily 26 mg of biochanin A, 16 mg of formononetin, 1 mg of genistein, and 0.5 mg of daidzein.
Refer to label instructions
Red clover has a long history of use for relieving coughs.
The mucilage of slippery elm gives it a soothing effect for coughs. Usnea also contains mucilage, which may be helpful in easing irritating coughs. There is a long tradition of using wild cherry syrups to treat coughs. Other traditional remedies to relieve coughs include bloodroot, catnip, comfrey (the above-ground parts, not the root), horehound, elecampane, mullein, lobelia, hyssop, licorice, mallow, (Malvia sylvestris), red clover, ivy leaf, pennyroyal (Hedeoma pulegioides, Mentha pulegium), onion, (Allium cepa), and plantain (Plantago lanceolata, P. major). None of these has been investigated in human trials, so their true efficacy for relieving coughs is unknown.
Refer to label instructions
Red clover has been used historically to treat people with eczema.
Traditional Chinese Medicine and Western folk medicine used this plant as a diuretic, a cough expectorant (an agent that promotes discharge of mucus from the respiratory passages), and an alterative.1 Alterative plants were considered beneficial for chronic conditions, particularly those afflicting the skin.
Red clover is known as an alterative agent—in other words, one that produces gradual beneficial changes in the body, usually by improving nutrition; also known as a “blood cleanser.” It is a traditional remedy for psoriasis and eczema. However, the mechanism of action and constituents responsible for red clover’s purported benefit in skin conditions are unknown.
Modern research has revealed that red clover also contains high amounts of isoflavones, such as biochanin A, formononetin, and genistein, which have weak estrogen-like properties.10 Modern research has focused on a red clover extract high in isoflavones as a possible treatment for symptoms associated with menopause and cardiovascular health in menopausal women. In a double-blind study, administration of 80 mg of isoflavones per day from red clover reduced the frequency of hot flashes in postmenopausal women. The benefit was noticeable after 4 weeks of treatment and became more pronounced after a total of 12 weeks.11 Another double-blind trial found that red clover improved cardiovascular function in menopausal women.12 Various laboratory studies suggest red clover isoflavones may help prevent prostate cancer.13 , 14 In a case study, use of red clover by a man with prostate cancer led to noticeable anticancer effects in his prostate after the cancer was surgically removed. Although the isoflavones in red clover may help prevent certain forms of cancer (for example, breast and prostate), further studies are needed before red clover is recommended for cancer patients.
Traditionally, red clover is taken as a tea, by adding 1 cup (250 ml) of boiling water to 2 to 3 teaspoons (10 to 15 grams) of dried flowers and steeping, covered, for ten to fifteen minutes.15 Three cups (750 ml) can be drunk each day. Red clover can also be used in capsule or tablet form, equivalent to 2 to 4 grams of the dried flowers. Also, 1/2 to 3/4 teaspoon (2 to 4 ml) of tincture three times per day may be taken. Standardized extracts providing 40 mg isoflavones per day are available as well.16
Certain medicines interact with this supplement.
Although there are no specific studies demonstrating interactions with anticoagulants, the following herbs contain coumarin-like substances that may interact with heparin and could conceivably cause bleeding.17 These herbs include dong quai, fenugreek, horse chestnut, red clover, sweet clover, and sweet woodruff. People should consult a healthcare professional if they’re taking an anticoagulant and wish to use one of these herbs.
Nonfermented red clover is relatively safe. However, fermented red clover may cause bleeding and should be avoided. Red clover supplements should be avoided by pregnant or breast-feeding women and their safety has not been established in young children and infants.
1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 177–8.
2. Crawford AM. The Herbal Menopause Book. Freedom, CA: Crossing Press, 1996.
3. Hudson TS, Standish L, Breed C, et al. Clinical and endocrinological effects of a menopausal botanical formula. J Naturopathic Med 1997;7(1):73–7.
4. Hirata JD, Swiersz LM, Zell B, et al. Does dong quai have estrogenic effects in postmenopausal women? A double-blind, placebo-controlled trial. Fertil Steril 1997;68:981–6.
5. Nestel PJ, Pomeroy S, Kay S, et al. Isoflavones from red clover improve systemic arterial compliance but not plasma lipids in menopausal women. J Clin Endocrinol Metab 1999;84:895–8.
6. Tice JA, Ettinger B, Ensrud K, et al. Phytoestrogen supplements for the treatment of hot flashes: the Isoflavone Clover Extract (ICE) Study: a randomized controlled trial. JAMA 2003;290:207–14.
7. van de Weijer PHM, Barentsen R. Isoflavones from red clover (Promensil®) significantly reduce menopausal hot flush symptoms compared with placebo. Maturitas 2002;42:187–93.
8. Lipovac M, Chedraui P, Gruenhut C, et al. Improvement of postmenopausal depressive and anxiety symptoms after treatment with isoflavones derived from red clover extracts. Maturitas 2010;65:258–261.
9. Atkinson C, Compston JE, Day NE, et al. The effects of phytoestrogen isoflavones on bone density in women: a double-blind, randomized, placebo-controlled trial. Am J Clin Nutr 2004;79:326–33.
10. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 177–8.
11. van de Weijer PHM, Barentsen R. Isoflavones from red clover (Promensil®) significantly reduce menopausal hot flush symptoms compared with placebo. Maturitas 2002;42:187–93.
12. Nestel PJ, Pomeroy S, Kay S, et al. Isoflavones from red clover improve systemic arterial compliance but not plasma lipids in menopausal women. J Clin Endocrinol Metab 1999;84:895–8.
13. Yanagihara K, Toge T, Numoto M, et al. Antiproliferative effects of isoflavones on human cancer cell lines established from the gastrointestinal tract. Cancer Res 1993;53:5815–21.
14. Stephens FO. Phytoestrogens and prostate cancer. Possible preventive role. Med J Australia 1997;167:138–40.
15. Foster S. Herbs for Your Health. Loveland, CO: Interweave Press, 1996, 76–7.
16. Nestel PJ, Pomeroy S, Kay S, et al. Isoflavones from red clover improve systemic arterial compliance but not plasma lipids in menopausal women. J Clin Endocrinol Metab 1999;84:895–8.
17. Miller LG, Murray WJ, eds. Herbal Medicinals: A Clinician’s Guide. New York: Pharmaceutical Products Press, 1999, 313–5.
Last Review: 11-07-2012
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