Red clover is a wild plant belonging to the legume family. Cattle and other animals graze on red clover. It has also been used medicinally to treat a number of conditions including cancer, whooping cough, respiratory problems, and skin inflammations, such as psoriasis and eczema. Health care practitioners believe that red clover "purified" the blood by acting as a diuretic (helping the body get rid of excess fluid) and expectorant (helping clear lungs of mucous), improving circulation, and helping cleanse the liver.
Modern scientific tests have shown that red clover contains isoflavones, plant-based chemicals that produce estrogen like effects in the body. Isoflavones have shown potential in the treatment of a number of conditions associated with menopause, such as hot flashes, cardiovascular health, and osteoporosis. However, as researchers have become aware of the side effects of taking estrogen, there is also some concern about the safety of isoflavones. Plus, evidence that red clover helps reduce any menopausal symptoms -- like hot flashes -- is mixed.
Red clover is a perennial herb that commonly grows wild in meadows throughout Europe and Asia, and has now been naturalized to grow in North America. The red flowers at the end of the branched stems are usually dried for therapeutic use.
Medicinal Uses and Indications
Red clover is a source of many nutrients including calcium, chromium, magnesium, niacin, phosphorus, potassium, thiamine, and vitamin C. Red clover is a rich source of isoflavones (chemicals that act like estrogens and are found in many plants).
Researchers theorize that red clover might help protect against heart disease, but studies in humans have not found strong evidence. Red clover isoflavones have been associated with an increase in "good" HDL cholesterol in pre and postmenopausal women, but other studies show conflicting results. One study found that menopausal women taking red clover supplements had stronger, more flexible arteries (called arterial compliance), which can help prevent heart disease. Red clover may also have blood-thinning properties, which keeps blood clots from forming. It appears to improve blood flow.
Researchers think that isoflavones, like those found in red clover, might help reduce symptoms of menopause, such as hot flashes and night sweats, because of their estrogen-like effects. So far studies have not been conclusive. Several studies of a proprietary extract of red clover isoflavones suggest that it may significantly reduce hot flashes in menopausal women. The largest study, however, showed no such effect.
As estrogen levels drop during menopause, a woman's risk for developing osteoporosis (significant bone loss) goes up. A few studies suggest that a proprietary extract of red clover isoflavones may slow bone loss and even boost bone mineral density in pre and perimenopausal women. But the evidence is preliminary, and more research is needed.
Based on its traditional use for cancer, researchers have begun to study the role of isoflavones from red clover in cancer prevention and treatment. Preliminary evidence suggests these isoflavones may stop cancer cells from growing or kill cancer cells in test tubes. Researchers theorize that red clover may help prevent some forms of cancer, such as prostate and endometrial cancer, because of the herb's estrogen-like effects, it might also contribute to the growth of some cancers, just as estrogen does. Until further research is done, doctors cannot recommend red clover to prevent cancer. Women with a history of breast cancer should not take red clover.
Traditionally, red clover ointments have been applied to the skin to treat psoriasis, eczema, and other rashes. Red clover also has a history of use as a cough remedy for children. More recently, studies have shown thatq women using red clover may also experience psychological benefits.
Dosage and Administration
Red clover is available in a variety of preparations, including teas, tinctures, tablets, capsules, liquid extract, and extracts standardized to specific isoflavone contents. It can also be prepared as an ointment for topical (skin) application. Due to lack of long-term studies, self treatment should not exceed 3 - 6 months without the supervision of a health care professional.
Red clover has been used traditionally as a short-term cough remedy for children. Products containing isolated red clover isoflavones are very different than the whole herb, however, and are not recommended for children. Do not give a child red clover without talking to your pediatrician first.
Dose may vary from person to person, but general guidelines are as follows:
- Dried herb (used for tea): 1 - 2 tsp dried flowers or flowering tops steeped in 8 oz. hot water for 1/2 hour; drink 2 - 3 cups daily
- Powdered herb (available in capsules): 40 - 160 mg per day, or 28 - 85 mg of red clover isoflavones
- Tincture (1:5, 30% alcohol): 60 - 100 drops (3 - 5 mL) 3 times per day; may add to hot water as a tea
- Fluid Extract (1:1): 1 mL 3 times per day; may add to hot water as a tea
- Standardized red clover isoflavone extracts: directions on product labels should be carefully followed
- Topical treatment (such as for psoriasis or eczema): an infusion, liquid extract, or ointment containing 10 - 15% flowerheads; apply as needed unless irritation develops. Do not apply to an open wound without a doctor's supervision.
Although some red clover isoflavones are being studied for a variety of conditions, it is important to remember that extracts of red clover isoflavones are very different from the whole herb. In fact, they represent only a small, highly concentrated part of the entire herb.
No serious side effects have been reported in people taking red clover for up to one year. General side effects may include headache, nausea, and rash. However, animals that graze on large amounts of red clover have become infertile. People who have been diagnosed with breast cancer should not use red clover without discussing it with their physician. Red clover may increase the risk of bleeding, particularly in those people who are taking blood-thinning medications.
Pregnancy and Breastfeeding
Pregnant or breastfeeding women should not take red clover.
Interactions and Depletions
Red clover may interfere with the body's ability to process some drugs that are broken down by liver enzymes. For that reason, you should check with your doctor before taking red clover.
Estrogens, hormone replacement therapy, birth control pills -- Red clover may increase the effects of estrogen.
Tamoxifen -- Red clover may interfere with tamoxifen.
Anticoagulants (blood thinners) -- Red clover may enhance the effect of these drugs, increasing the risk of bleeding. The same is true of herbs and supplements that have blood-thinning effects (such as ginkgo, ginger, garlic, and vitamin E).
Baber R, Bligh PC, Fulcher G, et al. The effect of an Isoflavone dietary supplement (P-081) on serum lipids, forearm bone density & endometrial thickness in post menopausal women [abstract]. Menopause. 1999a;6:326.
Baber RJ, Templeman C, Morton T, et al. Randomized, placebo-controlled trial of an isoflavone supplement and menopausal symptoms in women. Climacteric. 1999b;2(2):85-92.
Cassady JM, Zennie TM, Young-Heum C, et al. Use of a mammalian cell culture benzo(a)pyrene metabolism assay for the detection of potential anticarcinogens from natural products: Inhibition of metabolism by biochanin A, anisoflavone from Trifolium pratense L. Cancer Res. 1988;48:6257-6261.
Chedraui P, San Miguel G, Hidalgo L, Morocho N, Ross S. Effect of Trifolium pratense-derived isoflavones on the lipid profile of postmenopausal women with increased body mass index. Gynecol Endocrinol. 2008 Nov;24(11):620-4.
DerMarderosian A, ed. Red Clover. In: Facts and Comparisons The Review of Natural Products. 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2008
Duke JA. CRC Handbook of Medicinal Herbs. Boca Raton, Fla: CRC Press, Inc.; 2000:614.
Geller SE, Studee L. Soy and red clover for mid-life and aging. Climacteric. 2006 Aug;9(4):245-63.
Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm. 2000;57(13):1221-1227.
Howes JB, Sullivan D, Lai N. The effects of dietary supplementation with isoflavones from red clover on the lipoprotein profiles of postmenopausal women with mild to moderate hypercholesterolemia. Atherosclerosis. 2000;152(1):143-147.
Husband A. Red clover isoflavone supplements: safety and pharmacokinetics. Journal of the British Menopause Society. 2001;Supplement S1:4-7.
Jeri AR. The effect of isoflavones phytoestrogens in relieving hot flushes in Peruvian postmenopausal women. Paper presented at: 9th International Menopause Society World Congress on the Menopause; October 20, 1999; Yokahama, Japan.
Kuhn MA, Winston D. Herbal Therapy and Supplements. Philadelphia, Pa: Lippincott; 2008:365-369.
Lipovac M, Chedraui P, Gruenhut C, et al. The effect of red clover isoflavone supplementation over vasomotor and menopausal symptoms in postmenopausal women. Gynecol Endocrinol. 2012; 28(3):203-7.
Mannella P, Tosi V, Russo E, et al. Effects of red clover extracts on breast cancer cell migration and invasion. Gynecol endocrinol. 2012; 28(1):29-33.
McGuffin M, Hobbs C, Upton R, et al. Botanical Safety Handbook. Boca Raton, Fla: CRC Press LLC; 1997: 117.
Mueller M, Jungbauer A. Red clover extract: a putative source for simultaneous treatment of menopausal disorders and the metabolic syndrome. Menopause. 2008 Nov-Dec;15(6):1120-31.
Nachtigall LE. Isoflavones in the management of menopause. Journal of the British Menopause Society. 2001;Supplement S1:8-12.
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(3):895-898.
North American Menopause Society (NAMS). The role of isoflavones in menopausal health: consensus opinion of the North American Menopause Society. Menopause. 2000;7(4):215-229.
Occhiuto F, Pasquale RD, Guglielmo G, Palumbo DR, Zangla G, Samperi S, Renzo A, Circosta C. Effects of phytoestrogenic isoflavones from red clover (Trifolium pratense L.) on experimental osteoporosis. Phytother Res. 2007 Feb;21(2):130-4.
Panay N. Taking an integrated approach: managing women with phytoestrogens. Climacteric. 2011; 14(2):2-7.
Powles TJ, Howell A, Evans DG, McCloskey EV, Ashley S, Greenhalgh R, Affen J, Flook LA, Tidy A. Red clover isoflavones are safe and well tolerated in women with a family history of breast cancer. Menopause Int. 2008 Mar;14(1):6-12.
Rakel: Integrative Medicine, 2nd ed. Philadelphia, PA: Saunders Elsevier, Inc. 2007.
Stephens FO. Phytoestrogens and prostate cancer: possible preventive role. MJA. 1997;167:138-140.
Umland EM. Treatment strategies for reducing the burden of menopause-associated vasomotor symptoms. J Manag Care Pharm. 2008 Apr;14(3 Suppl):14-9. Review.
Woodside JV, Campbell MJ. Isoflavones and breast cancer. Journal of the British Menopause Society. 2001;Supplement S1:17-21.
Wuttke W, Rimoldi G, Christoffel J, Seidlova-Wuttke D. Plant extracts for the treatment of menopausal women: Safe? Maturitas. 2006 Nov 1;55 Suppl 1:S92-S100. Epub 2006 Aug 8.
Zava DT, Dollbaum CM, Blen M. Estrogen and progestin bioactivity of foods, herbs, and spices. Proc Soc Exp Biol Med. 1998;217(3):369-378.
Beebread; Cow clover; Cow grass; Meadow clover; Purple clover; Trifolium pratense
- Last Reviewed on 02/14/2013
- Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2013 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
This page was last updated: May 7, 2013