Red Clover
Background
Like
peas and beans, red clover belongs to the family of plants called
legumes. Red clover contains substances called isoflavones. Isoflavones
are phytoestrogens—compounds similar to the female
hormone estrogen.
Historically, red clover was used for a
variety of conditions including asthma, whooping cough, cancer, and
gout. Today, isoflavone extracts from red clover are most often used as
dietary supplements for menopausal symptoms, high cholesterol,
or osteoporosis.
The flowering tops of the red clover plant are
used to prepare extracts available in tablets or capsules, as well as
in teas and liquid forms.
How Much Do We Know?
There
have been several studies of red clover in people, but their results
haven’t provided clear evidence of any beneficial effects.
What Have We Learned?
Red clover has not been clearly shown to be helpful for any
health condition.
Most research indicates that taking red clover does not relieve
menopause symptoms such as hot flashes.
The
National Center for Complementary and Integrative Health (NCCIH) is
supporting research to develop better methods of identifying active
components in red clover and to evaluate possible interactions of red
clover with medications.
What Do We Know About Safety?
No
serious side effects have been reported in studies that evaluated red
clover for various health conditions for up to a year.
Because
red clover contains estrogen-like compounds, there’s a possibility that
long-term use would increase the risk of women developing cancer of the
endometrium (the lining of the uterus). However, short-term studies of
women who have taken red clover have not shown harmful changes in the
uterine lining.
Red clover may not be safe for women who are
pregnant or breastfeeding, for children, or for women who have breast
cancer or other hormone-sensitive cancers.
Keep in Mind
Tell
all your health care providers about any complementary or integrative
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.
Key References
- Krause
EC, Booth NL, Piersen CE, et al. Red clover. In: Coates PM, Betz JM,
Blackman MR, et al., eds. Encyclopedia of Dietary
Supplements. 2nd ed. New York, NY: Informa
Healthcare; 2010:665-679.
- Lethaby
A, Marjoribanks J, Kronenberg F, et al. Phytoestrogens for menopausal
vasomotor symptoms. Cochrane Database of Systematic
Reviews. 2013;(12):CD001395. Accessed at http://www.thecochranelibrary.com(link
is external) on
April 21, 2015.
- Red
clover. Natural Medicines Web site. Accessed at
naturalmedicines.therapeuticresearch.com/ on April 21, 2015.
[Database subscription].
-NIH