Red clover is a perennial plant with the scientific name Trifolium pratense. This wild herb also belongs to the legume family, along with beans and peas. Red clover is native to Europe and Asia but is now a naturalized plant in North America.
Red clover contains isoflavones—like biochanin A, formononetin, and genistein. Red clover is thought to work through these plant chemicals, which may have some estrogen activity. For this reason, isoflavones are also called phytoestrogens.
This article explains red clover benefits, the possible side effects and interactions, and why (like all supplements) consumers should research it carefully.
Use of Red Clover
Like many herbs, people may use red clover for various reasons. But there are several studies assessing red clover for the following potential uses.
Dietary supplements are not regulated like drugs in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. When possible, choose a supplement tested by a trusted third party, such as USP, ConsumerLabs, or NSF. However, even if supplements are third-party tested, that doesn’t mean they are necessarily safe for all or effective in general. Therefore, it is important to talk to your healthcare provider about any supplements you plan to take and check in about potential interactions with other supplements or medications.
Supplement Facts
- Active ingredients(s): Isoflavones—like biochanin A, formononetin, and genisteinAlternative name(s): Red clover, cow clover, meadow clover, wild clover, purple clover, Trifolium pratenseLegal status: Legal in most states (United States)Suggested dose: May vary based on condition or dosage formSafety considerations: Pregnancy, breastfeeding, and children. Caution use with blood thinners, hormones, and methotrexate. Red clover appears safe for long-term use (up to three years).
Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.
Menopausal Symptoms
In a systematic review and meta-analysis, red clover isoflavone extract reduced the number of hot flashes per day. However, more well-designed studies are still needed.
Bone Loss
In a small study in individuals assigned female at birth who were in menopause, red clover extract positively affected bone health. Bone mineral density (BMD) only decreased in individuals taking the placebo (a substance with no medication). BMD measures your bones’ strength and thickness (density or mass).
While this study shows promise, large and long-term studies are still needed.
Cancer
Preliminary research suggests that red clover might help treat prostate cancer.
In a mouse study, formononetin—a red clover isoflavone (a type of plant chemical)—had extra anti-prostate tumor effects when combined with the Taxotere (docetaxel) chemotherapy agent. These two medications were loaded into nanoparticles (nano-sized drug delivery system) and injected into the mice.
However, further studies in humans would be needed to confirm these results.
High Cholesterol
As previously mentioned, red clover contains isoflavones. In a meta-analysis (a collection of studies), isoflavones slightly lowered triglyceride levels compared to placebo. But isoflavones didn’t seem to have a significant effect on low-density lipoprotein (“bad cholesterol), high-density lipoprotein (“good cholesterol), or total cholesterol. Further study is warranted.
What Are the Side Effects of Red Clover?
Like any other medication or supplement, side effects are possible with red clover.
Common Side Effects
According to a small study, participants with menopause didn’t experience side effects when red clover extract was used for bone health.
However, in a meta-analysis of red clover’s potential use for high cholesterol, common side effects of isoflavones—like the ones in red clover—may include:
- Back pain
- Bloating
- Stomach pain
Severe Side Effects
A severe allergic reaction is a serious side effect possible with any medication. If you’re having a severe allergic reaction to red clover, symptoms may include breathing difficulties, itchiness, and rash.
While rare, other potential severe side effects may also include:
- Endometrial hyperplasia: In endometrial hyperplasia, there is an abnormal thickening of the endometrium. The endometrium is the lining of the uterus (womb). Symptoms may include irregular menstrual period bleeding, spotting, or post-menopausal bleeding.
- Breast cancer recurrence: Isoflavones—like the ones in red clover—may increase the chances of breast cancer returning. Symptoms of breast cancer may include breast skin changes, nipple discharge, and breast swelling or pain.
Call 911 and get medical help immediately if you’re having a severe allergic reaction or your symptoms are life-threatening.
Precautions
Your healthcare provider may advise against using red clover if any of the following applies to you:
- Severe allergic reaction: If you have a severe allergic reaction to red clover or its components (ingredients), you shouldn’t take this medication.
- Breast cancer: For certain types of breast cancer, endocrine (hormone) therapy is typically used after surgery. This is to prevent these types of breast cancer from coming back. Since red clover may interfere with endocrine therapy, red clover isn’t generally recommended.
- Pregnancy or breastfeeding: According to the National Center for Complementary and Integrative Health (NCCIH), red clover should be avoided while pregnant or breastfeeding. Reach out to your healthcare provider for a discussion on the benefits and risks of red clover in pregnancy or breastfeeding.
- Children: There is little information on the effects and safety of red clover in children.
- Older adults over 65: While older adults may have participated in some clinical trials, some of the study participants were individuals designated female at birth who were postmenopause. Moreover, some older adults may be sensitive to side effects from medications. For this reason, take red clover with caution.
Dosage: How Much Red Clover Should I Take?
While there are studies with red clover in humans, larger and well-designed studies are still necessary. For this reason, there are no guidelines on the appropriate dosage of red clover for any condition. Follow your healthcare provider’s recommendations or label instructions if you choose to take red clover.
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
What Happens If I Take Too Much Red Clover?
There is little information about red clover toxicity and overdoses in humans. But in a case report, red clover might be linked to severe bleeding and bruising side effects—similar to Coumadin (warfarin) toxicity. This warfarin-like toxicity may have resulted from five to six cups of red clover-containing herbal tea for two weeks.
If you think you’re experiencing an overdose or life-threatening symptoms, get medical help immediately.
Interactions
Use caution when taking red clover with the following:
- Blood thinners: Endometrial hyperplasia is a possible serious side effect of red clover, and symptoms may include abnormal bleeding. Large amounts of red clover might also be linked to severe bleeding and bruising. For these reasons, red clover may worsen the side effects of blood thinners, such as warfarin.
- Hormone therapy: Red clover contains isoflavones that may have some estrogen-like activity. For this reason, red clover may interact with endocrine (hormone) therapy for certain types of breast cancer, menopausal hormone therapy, and hormonal birth control.
- Methotrexate: Red clover might be linked to methotrexate toxicity. Methotrexate is a drug typically used for certain types of cancer, psoriasis, or rheumatoid arthritis.
It is essential to carefully read a supplement’s ingredient list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.
How to Store Red Clover
Since storage instructions may vary for different herbal products, carefully read the directions and packaging label on the container. But in general, keep your medications tightly closed and out of the reach of children and pets, ideally locked in a cabinet or closet. Try to store your medicines in a cool and dry place.
Discard after one year or as indicated on the packaging. Avoid pouring unused and expired products down the drain or in the toilet. Visit the FDA’s website to know where and how to discard all unused and expired products. You can also find disposal boxes in your area.Ask your pharmacist or healthcare provider if you have any questions about the best ways to dispose of your medications or supplements.
Similar Supplements
Some of red clover’s potential uses may include relieving menopausal symptoms and lowering high cholesterol. And other potentially similar supplements may include the following:
Black cohosh
People may use black cohosh for several reasons, including menopausal hot flashes. A review suggested that black cohosh extract may relieve menopausal symptoms.
In general, black cohosh appears safe for up to 12 months of use. Like red clover, black cohosh’s side effects may include stomach upset, cramping, and vaginal spotting. And like red clover, black cohosh isn’t recommended for people with breast cancer. What’s more, people with liver problems should also avoid black cohosh. And there is limited safety information about black cohosh use during pregnancy or while breastfeeding.
Evening primrose
People may use evening primrose for various reasons, including relieving menopausal symptoms. Presently, there’s not enough evidence to support evening primrose for any medical condition—like menopause.
In general, evening primrose appears to be safe. And unlike red clover, evening primrose might be safe during pregnancy or while breastfeeding. But similar to red clover, many of evening primrose’s common side effects are related to the digestive system—like bloatedness or stomach pain.
Flaxseed
People may use flaxseed for several reasons, including high cholesterol and menopause. According to a review, flaxseed helped with heart and blood vessel conditions—like high cholesterol. But it’s unsure about flaxseed oil’s effects on heart and blood vessel conditions. And as for menopause, flaxseed’s results are mixed.
As for safety, raw and unripe flaxseeds may typically have toxic chemicals. While small amounts of flaxseed supplements might generally be safe, flaxseed in very large amounts may be unsafe during pregnancy. And there’s little information about flaxseed’s safety while breastfeeding. As for side effects, flaxseed may cause constipation or diarrhea.
Sources of Red Clover & What to Look For
Don’t take these supplements together or with red clover until you talk with your healthcare provider first. They can help prevent possible interactions and side effects. They can also ensure that you’re giving these supplements a good trial at appropriate doses.
Frequently Asked Questions
- What is the most common dosage form for red clover?
- Red clover is available in several different dosage forms—with liquid being the most common.
- Is red clover available from manufacturers in the United States?
- Yes. Several manufacturers make red clover products in the United States.
- Can red clover help with infertility?
- One of red clover’s traditional uses was improved fertility.While there are limited red clover studies on human fertility, a review of several animal studies. In this review, isoflavones—like the ones in red clover—may negatively affect fertility. Interestingly, the negative effects on fertility aren’t dependent on the isoflavone dose—but likely on the isoflavone type.
- Does red clover cause weight gain?
- Based on a systematic review and meta-analysis of phytoestrogens in individuals designated female at birth who were in postmenopause, phytoestrogens—like the ones from red clover—weren’t typically linked to weight gain.But phytoestrogens might be connected to slight weight gain in study participants with certain medical conditions, such as diabetes, hypertension (high blood pressure), or hyperlipidemia (high cholesterol).What’s more, daidzein—a particular phytoestrogen in red clover—might have more effect on weight gain when compared to other phytoestrogens.
- How do I take red clover safely?
- To take herbal medications like red clover safely, inform your healthcare providers and pharmacists about any medication changes. This includes over-the-counter (OTC), herbal, natural medications, and supplements.They can help prevent possible interactions and side effects. They can also ensure that you’re giving red clover a good trial at appropriate doses.
Red clover is available in several different dosage forms—with liquid being the most common.
Yes. Several manufacturers make red clover products in the United States.
One of red clover’s traditional uses was improved fertility.
Based on a systematic review and meta-analysis of phytoestrogens in individuals designated female at birth who were in postmenopause, phytoestrogens—like the ones from red clover—weren’t typically linked to weight gain.
To take herbal medications like red clover safely, inform your healthcare providers and pharmacists about any medication changes. This includes over-the-counter (OTC), herbal, natural medications, and supplements.They can help prevent possible interactions and side effects. They can also ensure that you’re giving red clover a good trial at appropriate doses.
There are several different sources of red clover.
Food Sources of Red Clover
Red clover is naturally available as a wild plant in the legume family. You may see this dried herb used for tea.
In general, dietary changes may interact with your medications or affect your medical conditions. For this reason, talk with your healthcare provider first. They will help you safely make any dietary changes.
Red Clover Supplements
Red clover is available in various forms, including capsules and tablets. If you have difficulties swallowing pills, red clover is also available in the following dosage forms:
- LiquidPowder
There are also vegan and vegetarian options. The specific product you choose will depend on your preference and what you hope to get in terms of effects. Each product may work a bit differently, depending on the form. So, following your healthcare provider’s recommendations or label directions is essential.
Summary
Red clover is an herb that may ease menopausal symptoms, reduce bone loss, treat prostate cancer, and decrease cholesterol. While results from some clinical trials are promising, large and well-designed studies are still needed to confirm these uses.
For this reason, consumers should tread carefully and be aware of potential side effects and interactions. Before taking red clover, talk with your pharmacist or healthcare provider to help you safely achieve your health goals.
