(3S)-3-(4-Hydroxyphenyl)-7-chromanol , 4',7-isoflavandiol, 7,4'-dihydroxy-isoflavan, 7-hydroxy-3-(4'-hydroxyphenyl)-chroman, SE5-OH, S-equol.
Equol comes from soy. When soy is eaten certain bacteria in the gut change chemicals contained in soy to equol. However, only 30-60% of people are able to break down soy chemicals to form equol. Some studies have shown that people capable of breaking soy down to form equol get more health benefits from soy. These people are called “equol producers.”
Equol is used for reducing menopause symptoms such as hot flashes in women. It is also used to prevent weak bones (osteoporosis) and to reduce wrinkled skin. Other uses include preventing metabolic syndrome, preventing diseases of the heart and blood vessels, treating high cholesterol, treating diabetes, and preventing breast and prostate cancer.
Equol comes in two different forms, R-equol or S-equol. Most commercial equol products contain S-equol.
How does it work?
Equol is a chemical that has some effects that are similar to the hormone estrogen, but it is much less potent than estrogen.
Possibly Effective for...
- Menopausal symptoms. Taking S-equol by mouth appears to improve symptoms related to menopause including hot flashes in women who cannot produce equol from soy.
Insufficient Evidence to Rate Effectiveness for...
- Metabolic syndrome. There is early evidence that S-equol might lower some of the health risks that make overweight men and women more likely to develop metabolic syndrome.
- Reducing the risk of osteoporosis (weak bones). There is some evidence that taking S-equol might slow bone loss in women near or beyond menopause who cannot produce equol from soy.
- Wrinkled skin. There is some evidence that S-equol can reduce crow's-feet wrinkles in postmenopausal women who are unable to produce equol from soy.
- Breast cancer.
- Heart disease.
- High cholesterol.
- Prostate cancer.
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).
Breast Cancer: The effects of equol in people with breast cancer are unclear. Some research finds that equol might “feed” certain breast cancers because it can act like estrogen. Other studies have found that equol seems to protect against breast cancer. Because there isn't enough reliable information about the effects of equol in women with breast cancer, a history of breast cancer, or a family history of breast cancer, it is best to avoid using equol until more is known.
Birth control pills (Contraceptive drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Some birth control pills contain estrogen. In the body, estrogen can either be free or it can be attached to certain proteins. The free estrogen is the type that works in the body. Equol might increase the amount of free estrogen. Taking equol along with birth control pills might increase the risk of side effects from the birth control pills. These side effects include headaches, breast tenderness, painful periods, and weight gain.
EstrogensInteraction Rating: Moderate Be cautious with this combination.Talk with your health provider.
In the body, estrogen can either be free or it can be attached to certain proteins. The free estrogen is the type that works in the body. Equol might increase the amount of free estrogen in the body. Taking equol along with estrogen might increase the risk of side effects from estrogen replacement therapy. These side effects include headaches, breast tenderness, and weight gain.
Some estrogen pills include conjugated equine estrogens (Premarin), ethinyl estradiol, estradiol, and others.
TestosteroneInteraction Rating: Moderate Be cautious with this combination.Talk with your health provider.
In the body, testosterone can either be free or it can be attached to certain proteins. The free testosterone is the type that works in the body. Equol might increase the amount of free testosterone in the body. Taking equol along with testosterone might increase the risk of side effects from testosterone replacement therapy. These side effects include acne, headaches, weight gain, and growth of breasts in men.
Water pills (Diuretic Drugs)Interaction Rating: Minor Be cautious with this combination.Talk with your health provider.
The following doses have been studied in scientific research:
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Brown NM, Belles CA, Lindley SL, et al. The chemopreventive action of equol enantiomers in a chemically induced animal model of breast cancer. Carcinogenesis 2010;31:886-93. View abstract.
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Martinez RM, Gimenez I, Lou JM, et al. Soy isoflavonoids exhibit in vitro biological activities of loop diuretics. Am J Clin Nutr 1998;68:1354S-57S. View abstract.
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Oyama A, Ueno T, Uchiyama S, et al. The effects of natural S-equol supplementation on skin aging in postmenopausal women: a pilot randomized placebo-controlled trial. Menopause 2012;19:202-10. View abstract.
Setchell KD, Brown NM, Lydeking-Olsen E. The clinical importance of the metabolite equol-a clue to the effectiveness of soy and its isoflavones. J Nutr 2002;132:3577-84. View abstract.
Setchell KD, Clerici C, Lephart ED, et al. S-equol, a potent ligand for estrogen receptor beta, is the exclusive enantiomeric form of the isoflavone metabolite produced by human intestinal bacterial flora. Am J Clin Nutr 2005;81:1072-9. View abstract.
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Shi J, Ji A, Cao Z, et al. Equol induced apoptosis of human breast cancer MDA-MB-231 cell by inhibiting the expression of nuclear factor-kappaB. Wei Sheng Yan Jiu 2011;40:95-8. View abstract.
Tousen Y, Ezaki J, Fujii Y, et al. Natural S-equol decreases bone resorption in postmenopausal, non-equol-producing Japanese women: a pilot randomized, placebo-controlled trial. Menopause 2011;18:563-74. View abstract.
Usui T, Tochiya M, Sasaki Y, et al. Effects of natural S-equol supplements on overweight or obesity and metabolic syndrome in the Japanese, based on sex and equol status. Clin Endocrinol (Oxf) 2013;78:365-72. View abstract.
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