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This fact sheet provides basic information about red clover—common names, what the science says, potential side effects and cautions, and resources for more information.
Like peas and beans, red clover belongs to the family of plants called legumes. Red clover contains phytoestrogens—compounds similar to the female hormone estrogen. Historically, red clover has been used for cancer and respiratory problems, such as whooping cough, asthma, and bronchitis. Currently, red clover is used as a traditional or folk remedy for menopausal symptoms, breast pain associated with menstrual cycles, high cholesterol, osteoporosis, and symptoms of prostate enlargement.
The flowering tops of the red clover plant are used to prepare extracts available in tablets and capsules, as well as in teas and liquid forms.
What the Science Says
- Several small studies of red clover for menopausal symptoms had mixed results; however, most of these studies had design flaws. A large clinical trial and several reviews of the research literature concluded that red clover had no significant beneficial effects on menopausal symptoms.
- There is not enough scientific evidence to determine whether red clover is effective for any other health conditions.
- NCCIH is studying red clover to learn more about its active components and how they might work in the body, including how red clover isoflavones may affect human prostate cells and the safety and effectiveness of red clover for menopausal symptoms.
Side Effects and Cautions
- Red clover seems to be safe for most adults when used for short periods of time. No serious adverse effects have been reported.
- Because red clover contains estrogen-like compounds, there is a possibility that its long-term use would increase the risk of women developing cancer of the lining of the uterus. However, studies to date have been too brief (less than 6 months) to evaluate whether red clover has estrogen-like effects on the uterus.
- It is unclear whether red clover is safe for women who are pregnant or breastfeeding, or who have breast cancer or other hormone-sensitive cancers.
- Tell all your health care providers about any complementary health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care. For tips about talking with your health care providers about complementary health approaches, see NCCIH's Time to Talk campaign.
For More Information
The NCCIH Clearinghouse provides information on NCCIH and complementary health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.
A service of the National Library of Medicine (NLM), PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals.
Office of Dietary Supplements (ODS), National Institutes of Health (NIH)
ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public. Its resources include publications (such as Dietary Supplements: What You Need to Know), fact sheets on a variety of specific supplement ingredients and products (such as vitamin D and multivitamin/mineral supplements), and the PubMed Dietary Supplement Subset.
PubMed Dietary Supplement Subset: ods.od.nih.gov/Research/PubMed_Dietary_Supplement_Subset.aspx
NIH National Library of Medicine's MedlinePlus
- Booth NL, Piersen CE. Red clover (Trifolium pratense). In: Coates P, Blackman M, Cragg G, et al., eds. Encyclopedia of Dietary Supplements. New York, NY: Marcel Dekker; 2005:587–602.
- Fugh-Berman A, Kronenberg F. Red clover (Trifolium pratense) for menopausal women: current state of knowledge. Menopause. 2001;8(5):333–337.
- Lethaby AE, Brown J, Marjoribanks J, et al. Phytoestrogens for vasomotor menopausal symptoms. Cochrane Database of Systematic Reviews. 2007;(4):CD001395.
- Nelson HD, Vesco KK, Haney E, et al. Nonhormonal therapies for menopausal hot flashes: systematic review and meta-analysis. Journal of the American Medical Association. 2006;295(17):2057–2071.
- Red clover. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on July 22, 2009.
- Red clover (Trifolium pratense). Natural Standard Database Web site. Accessed at www.naturalstandard.com on July 22, 2009.
- Tice JA, Ettinger B, Ensrud K, et al. Phytoestrogen supplements for the treatment of hot flashes: the Isoflavone Clover Extract (ICE) study. Journal of the American Medical Association. 2003;290(2):207–214.
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