Red Clover: Benefits, Uses, and Side Effects

Red clover is a dark-pink herbaceous plant originating from Europe, Asia, and North Africa. Plus, it’s now popular throughout South America as a fodder crop to improve soil quality (1).

The flowering portion of red clover is used decoratively as an edible garnish or extract, and it can be extracted into essential oils (2).

Finally, it’s widely used as a traditional medicine to treat osteoporosis, heart disease, arthritis, skin disorders, cancer, respiratory problems like asthma, and women’s health issues, such as menstrual and menopausal symptoms.

However, little research supports these uses.

Summary

Red clover is a dark-pink flowering plant that’s used in traditional medicine to treat menopause symptoms, asthma, heart disease, skin disorders, and even cancer.

Despite limited scientific evidence, red clover is used to treat a variety of conditions.

Bone health

Osteoporosis is a condition in which your bones exhibit low bone mineral density (BMD) and have become weak (3).

As a woman reaches menopause, a decline in reproductive hormones — namely estrogen — can lead to increased bone turnover and a decrease in BMD (4, 5).

Red clover contains isoflavones, which are a type of phytoestrogen — a plant compound that can weakly mimic estrogen in the body. Some research has shown a connection between isoflavone intake and a decrease in osteoporosis risk (6, 7, 8).

A 2015 study in 60 premenopausal women found that taking 5 ounces (150 mL) of red clover extract containing 37 mg of isoflavones daily for 12 weeks led to less BMD loss in the lumbar spine and neck, compared with the placebo group (9).

Older studies have also shown improvements in BMD after taking red clover extract (10, 11).

However, a 2015 study in 147 postmenopausal women found that taking 50 mg of red clover daily for 1 year resulted in no improvements in BMD, compared with the placebo group (12).

Likewise, other studies have failed to find that red clover can help treat BMD (13, 14).

Due to the large number of conflicting studies, more research is needed.

Menopausal symptoms

Red clover’s high isoflavone content is believed to help lower menopause symptoms, such as hot flashes and night sweats.

Two review studies found that 40–80 mg of red clover (Promensil) per day may help alleviate hot flashes in women with severe symptoms (5 or more per day) by 30–50%. Still, many studies were funded by supplement companies, which may lead to bias (14, 15).

Another study observed a 73% decrease in hot flashes within 3 months after taking a supplement containing numerous herbs, including red clover. Yet, due to the large number of ingredients, it’s unknown whether red clover played a role in these improvements (16).

Red clover has also shown mild improvements in other menopausal symptoms, such as anxiety, depression, and vaginal dryness (14, 17, 18).

Yet, numerous studies have shown no improvements in menopausal symptoms after taking red clover, compared with a placebo (19, 20, 21, 22, 23).

Currently, there’s no clear evidence that supplementing with red clover will improve menopause symptoms. Higher quality, third-party research is needed (24).

Skin and hair health

Red clover extract has been used in traditional medicine to promote skin and hair health.

In a randomized study in 109 postmenopausal women, participants reported significant improvements in hair and skin texture, appearance, and overall quality after taking 80 mg of red clover extract for 90 days (25).

Another study in 30 men showed a 13% increase in the hair growth cycle (anagen) and a 29% decrease in the hair loss cycle (telogen) when a 5% red clover extract was applied to the scalp for 4 months, compared with the placebo group (26).

Though promising, more research is needed.

Heart health

Some preliminary research has shown red clover may improve heart health in postmenopausal women.

One 2015 study in 147 postmenopausal women indicated a 12% decrease in LDL (bad) cholesterol after taking 50 mg of red clover (Rimostil) daily for 1 year (27).

One review of studies in postmenopausal women taking red clover for 4–12 months showed a significant increase in HDL (good) cholesterol and a decrease in total and LDL (bad) cholesterol (28).

However, a 2020 review found red clover did not reduce LDL (bad) cholesterol or increase HDL (good) cholesterol (29).

Despite some promising results, the authors argued that many studies were small in sample size and lacked proper blinding. Therefore, higher quality research is needed (29).

Moreover, these studies were performed in older, menopausal women. Thus, it’s unknown whether these effects apply to the general population.

Other claims

Many proponents of red clover claim it can help with weight loss, cancer, asthma, whooping cough, arthritis, and other conditions.

However, limited evidence shows that red clover helps with any of these illnesses.

Summary

Red clover may help decrease menopausal hot flashes, though more research is needed. There’s not enough research showing it can improve cholesterol levels, strengthen bones, promote weight loss, or treat cancer, asthma, or other conditions.

Red clover is generally recognized as safe by the Food and Drug Administration (FDA), and most studies have found it to be well tolerated. Nevertheless, you should be aware of its side effects, drug interactions, and risks for certain populations.

Side effects

Though rare, potential side effects include vaginal spotting, prolonged menstruation, skin irritation, nausea, and headache. Additionally, there have been a few case reports of rare but dangerous side effects of red clover (20).

A 2007 report noted a 53-year-old woman had a subarachnoid hemorrhage — a type of stroke — after taking a supplement containing 250 mg of red clover, as well as eight other herbs, to treat hot flashes. That said, the hemorrhage could not be directly linked to red clover (30).

A 52-year-old woman reported severe stomach pain and vomiting after taking 430 mg of red clover for 3 days. The doctors believe red clover interfered with a psoriasis medication known as methotrexate. After stopping the red clover, she made a full recovery (31).

At-risk populations

Those with hormone-sensitive conditions, such as breast cancer, ovarian cancer, or endometriosis, should speak to their healthcare provider before taking red clover due to its estrogenic activity (32).

Still, a 3-year, double-blind study found taking 40 mg of red clover daily to be safe for women with a family history of breast cancer. Compared with the placebo group, there was not an increased risk of breast cancer, endometrial thickness, or hormonal changes (33).

Despite this study, it’s important to speak with your healthcare provider before taking red clover to ensure that it’s safe and right for you.

Additionally, no safety data on red clover among children or women who are pregnant or breastfeeding is available. Therefore, it should be avoided (34).

Finally, red clover may slow blood clotting and should be avoided by those with bleeding disorders. Further, always be sure to tell your healthcare provider about any medications or herbal remedies you’re taking if you’re going to have surgery (35).

Drug interactions

Many natural herbs can interfere with the effectiveness of medications.

In particular, red clover may interact with oral contraceptives, methotrexate, hormone replacement therapy medications, tamoxifen, blood thinners like aspirin or Plavix, among others (31, 36).

A recent study in 88 women taking the breast cancer medication tamoxifen found red clover did not result in any drug interactions or serious side effects, suggesting it does not interfere with anti-estrogen medications (37).

Despite this, great caution should be used when taking red clover and tamoxifen until there’s more clinical safety data available (38).

Due to the wide range of potential drug interactions with red clover and limited data on the subject, always speak with a healthcare professional before starting any new supplements.

Summary

Though generally recognized as safe, red clover has minor estrogenic properties and should be avoided by those who are pregnant or breastfeeding, as well as people with bleeding disorders or who take hormone replacement therapy or other medications.

Red clover is usually found as a supplement or tea using dried flower tops. They’re also available in tinctures and extracts. You can buy them in most health food stores or online.

Most red clover supplements are found in 40–80-mg doses based on clinical research and safety data. Therefore, be sure to follow the recommended dose on the package.

To make red clover tea, add 4 grams of dried flower tops (or red clover tea bags) to 1 cup (250 mL) of boiling water and steep for 5–10 minutes. Due to reports of side effects with 5 cups (1.2 liters) per day, it’s best to limit your daily intake to 1–3 cups (240–720 mL) (35).

Though many people enjoy red clover tea, no data shows it has the same potential health effects as concentrated forms of red clover, such as supplements and extracts.

Summary

Red clover can be taken as a supplement, extract, or tea. Be sure to follow the instructions on the label and speak with a healthcare professional before trying red clover.

Red clover is an herb used in traditional medicine to treat a wide range of health issues, such as hot flashes, osteoporosis, arthritis, and skin and hair disorders.

Some research has found taking 40–80 mg of red clover daily may help reduce severe menopausal hot flashes. However, beyond this, little evidence supports using red clover to treat other health conditions.

Though it has a good safety profile, some side effects include nausea, vomiting, headache, and vaginal spotting.

Furthermore, due to its minor estrogenic properties, those who are pregnant or breastfeeding, as well as people with hormone-sensitive conditions or bleeding disorders, should avoid its use.

To protect your health, always speak to your healthcare provider before taking red clover.