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.
Red clover has been used
in connection with the following conditions (refer to the individual
health concern for complete information):
Reliable
and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies
suggesting a health benefit or minimal health benefit. For an herb, supported by traditional use but minimal
or no scientific evidence. For a supplement, little scientific support and/or minimal health
benefit.
Historical or traditional use (may
or may not be supported by scientific studies)
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.
Active constituents
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 genistein, which have weak estrogen-like properties.2 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.3 Another
double-blind trial found that red clover improved cardiovascular function in menopausal
women.4 Various laboratory studies and one case report of a man with prostate
cancer suggest red clover isoflavones may help prevent cancer.56 In another 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.
How much is usually taken?
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.7 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.8
Are there any side effects or interactions?
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.
Are there any drug
interactions?
Certain medicines may interact with red clover. Refer to drug interactions for a list of those medicines.
References (To view, roll mouse over the "References" heading; to hide, click on the heading)
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. 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.
3. 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.
4. 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.
5. 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.
6. Stephens FO. Phytoestrogens and prostate cancer. Possible preventive
role. Med J Australia 1997;167:138–40.
7. Foster S. Herbs for Your Health. Loveland, CO: Interweave
Press, 1996, 76–7.
8. 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.
The information presented in Aisle7 is for informational purposes only.
It is based on scientific studies (human, animal, or in vitro), clinical experience,
or traditional usage as cited in each article. The results reported may not necessarily occur
in all individuals. For many of the conditions discussed, treatment with prescription or over
the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist
for any health problem and before using any supplements or before making any changes in
prescribed medications. Information expires February 2010.
Reliable
and relatively consistent scientific data showing a substantial health benefit.