Red clover is a perennial herb that commonly grows wild in meadows throughout Europe and Asia, and has 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 HDL ("good") 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 been mixed. Several studies of a proprietary extract of red clover isoflavones suggest that it may significantly reduce hot flashes in menopausal women. However, the largest study showed no 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. However, 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 has also been used as a cough remedy for children. More recently, studies have shown that women using red clover may 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 to 6 months without the supervision of a health care professional.Pediatric
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.Adult
Dose may vary from person to person, but general guidelines are as follows:
- Dried herb (used for tea): 1 to 2 tsp dried flowers or flowering tops steeped in 8 oz. hot water for 1/2 hour; drink 2 to 3 cups daily
- Powdered herb (available in capsules): 40 to 160 mg per day, or 28 to 85 mg of red clover isoflavones
- Tincture (1:5, 30% alcohol): 60 to 100 drops (3 to 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: follow directions on product labels carefully
- Topical treatment (such as for psoriasis or eczema): an infusion, liquid extract, or ointment containing 10 to 15% flower heads; 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 1 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, and 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).
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