6 Incredible Milk Thistle Benefits Backed by Science

author avatar Dr. Eric Berg 12/04/2023

Milk thistle is generally considered to be a pesky weed—but did you know that this prickly plant contains powerful flavonoids that can promote liver function, lower cancer risk, and may improve insulin resistance?

Let’s look at six milk thistle benefits and learn how to use milk thistle supplements to promote a healthy body. 

Milk thistle flowers

What is milk thistle?

Milk thistle, also known as mary thistle, is a flowering herb that belongs to the Asteraceae family and is closely related to daisies, marigolds, dandelions, and artichokes.

They have large, spiky leaves and tall stems topped by distinct purple flowers that produce small, mottled seeds.  

Milk thistles are native to the Mediterranean region but have spread to many parts of the world, where they’re typically considered an invasive weed species. 

Milk thistle seeds contain high concentrations of silymarin, a group of bioactive compounds with potent anti-inflammatory and antioxidant properties linked to several potential health benefits. 

The use of milk thistle for medicinal purposes dates back centuries, and records indicate that milk thistle extract has been used to treat snake bites, manage jaundice, and improve liver and gallbladder function. 

Watch the video below to learn more about the amazing benefits of milk thistle for liver health. 

Milk Thistle: The Amazing Herb for Your Liver

6 incredible milk thistle benefits

Milk thistle's long-standing use in traditional and folk medicine has ignited considerable scientific interest. 

Increasingly more milk thistle research is being conducted, and studies consistently show that silymarin, a bioactive flavonoid complex derived from the seeds of milk thistles, can positively affect various physiological functions.

Here are six science-backed benefits of milk thistle. 

1. Promotes liver health  

Silymarin is a complex of flavonoids, including silybin, silydianin, and silychristin, with several potential benefits for liver function.

The liver is responsible for metabolizing and detoxifying metabolic by-products, hormones, alcohol, drugs, toxins, and heavy metals, which generates reactive oxygen species (ROS) and oxidative stress

ROS are volatile molecules that can damage liver cells and cause liver inflammation, which impairs normal liver function and increases the risk of metabolic disorders, liver cancer, and cirrhosis.  

Evidence published in Annals of Medicine suggests that silymarin has potent antioxidant properties that can neutralize ROS, which protects from liver damage, enhances detoxification processes, and promotes overall liver function.

Because of its ability to protect liver cells from oxidation, taking milk thistle may be particularly beneficial for individuals with fatty liver and alcoholic liver disease, which are health conditions characterized by elevated ROS levels and liver inflammation.

Human liver illustration

2. Strengthen liver cells 

Not only does milk thistle promote healthy liver function, but it’s also believed that silymarin can help regenerate liver tissue.

Silymarin may increase DNA and protein production in hepatocytes, which strengthens the outer membrane of liver cells and stimulates the regeneration of liver tissue.

A study published in Advances in Therapy confirms the benefits of milk thistle for liver regeneration and concludes, “Treatment with silymarin should be initiated early in patients with fatty liver disease, chronic hepatitis, and acute liver failure when the regenerative potential of the liver is still high.” 

3. May improve insulin resistance 

Increasingly more evidence suggests that milk thistle may be a natural way to promote balanced blood sugar levels and metabolic health.

The liver plays a critical role in glucose metabolism and blood sugar regulation, and poor liver function and inflammation can contribute to insulin resistance, the primary cause of diabetes.

Milk thistle promotes overall liver function linked to enhanced cellular sensitivity to insulin, which is essential to maintaining blood sugar balance.

In addition, silymarin has powerful anti-inflammatory effects that inhibit certain proinflammatory molecules linked to insulin resistance, which explains why milk thistle can help lower blood sugar levels and reduce the risk of diabetes.   

Evidence published in Annals of Hepatology reports that silymarin treatment improved insulin resistance and several other metabolic health markers in patients with fatty liver disease.     

4. Potential anti-cancer properties

According to research published in the Journal of Evidence-Based Integrative Medicine, milk thistle may reduce the risk of liver cancer.

“Because of its role in metabolism and detoxification, the liver is exposed to elevated levels of ROS and inflammation,” explains Dr. Berg. “This can damage DNA and impair cellular repair mechanisms linked to an increased risk of cancer development.” 

Silymarin has antioxidants and anti-inflammatory properties that protect the liver from ROS and has been found to directly inhibit the growth and proliferation of cancer cells in liver tissue. 

Cardiovascular system

5. Supports vascular function    

Evidence published in Pharmaceutical Biology suggests that silymarin enhances the production and activity of nitric oxide, a potent vasodilator that promotes cardiovascular health.

Nitric oxide promotes vascular health by relaxing blood vessels, which improves blood flow and regulates blood pressure.

Because of its role in maintaining vascular tone, nitric oxide helps lower the risk of hypertension, varicose veins, atherosclerosis, and stroke. 

6. Promotes bile flow and gallbladder health

Bile is produced in liver cells and stored in the gallbladder and plays a crucial role in the digestion and absorption of dietary fats and fat-soluble vitamins.

Optimal gallbladder function is closely connected to liver health, and various studies have shown that milk thistle supports liver function, which is vital for adequate bile production and gallbladder health.

In addition, silymarin's anti-inflammatory effects may help reduce gallbladder inflammation, which lowers the risk of gallstones and other gallbladder issues.

Milk thistle supplements

Is milk thistle safe to take?

Milk thistle supplements are generally considered safe when taken in appropriate dosages. 

A study published in Integrated Cancer Reviews investigated the safety of milk thistle use and concluded, “Milk thistle extracts are safe and well tolerated, and toxic or adverse effects seem to be minimal.”

However, it's important to be aware of potential side effects and interactions before incorporating this herbal remedy into your wellness routine. 

Potential side effects

Gastrointestinal issues such as bloating, indigestion, or abdominal discomfort are the most common side effects of herbal supplements containing milk thistle.

However, these symptoms are usually mild and can typically be managed by taking milk thistle supplements with food. 

While allergic reactions are rare, some people are sensitive to milk thistle, and it’s crucial that you seek medical attention immediately if you develop itching, swelling, or difficulty breathing after taking milk thistle-containing products. 

Possible drug interactions

Milk thistle can affect a group of liver enzymes responsible for the metabolism and detoxification of certain drugs, including statins, antipsychotics, and immunosuppressants.

In addition, milk thistle has the potential to lower blood sugar levels, which increases the risk of hypoglycemia in individuals who are taking antidiabetic medications. 

If you are considering using milk thistle supplements, it’s critical to consult a healthcare provider if you are taking prescription medications or have an underlying health condition to minimize the risk of side effects. 

Magnifying glass over caution sign

Who shouldn’t take milk thistle?

The safety of milk thistle during pregnancy has not yet been well established, and the National Center for Complementary and Integrative Health (NCCIH) recommends that pregnant and breastfeeding mothers avoid milk thistle. 

Milk thistle belongs to the Asteraceae genus, and individuals with a known allergy to other members of this plant family, such as daisies, asters, marigolds, and artichokes, may be at increased risk of allergic reactions to milk thistle.   

Milk thistle can have mild estrogenic effects, which may worsen ovarian and breast cancer, and people with a history of hormone-related health conditions should avoid milk thistle products.    

Woman reading a product label

How do you take milk thistle?

Milk thistle supplements are widely available and can be taken as capsules, pills, liquid extracts, or powder.

Powders and liquids can be added to smoothies or water, making them an excellent option to incorporate milk thistle into your daily dietary routine. 

Capsules and pills, on the other hand, contain pre-measured doses, which helps you know exactly how much milk thistle you are taking.

Determining the best milk thistle dosage for your needs depends on your overall health status, the specific health condition being addressed, and the potency of the milk thistle supplement you are using. 

A report released by the European Medicines Agency (EMA) suggests a milk thistle dose ranging between 200 and 400 milligrams, taken two to three times daily with food. 

However, it’s crucial to carefully follow the instructions of the milk thistle product you are using and start with a lower dosage and gradually increase towards the recommended intake to minimize the risk of side effects.

Ground milk thistle seeds on a wooden spoon

Key takeaways

Milk thistle plant extracts have been used to treat snake bites, mushroom poisoning, and liver disease for centuries.  

Studies have confirmed milk thistle benefits for health and found that silymarin, a complex of flavonoids found in milk thistle seeds, is associated with improved liver health and detoxification, better blood sugar balance, and enhanced gallbladder function.


1. What are the top milk thistle benefits?

Milk thistle contains silymarin, a group of phytochemicals with powerful antioxidant and anti-inflammatory properties.

Silymarin has been found to promote liver health by protecting liver cells from inflammation, enhancing detoxification, and stimulating the regeneration of liver tissue. 

2. What does milk thistle do for your body?

Taking milk thistle can promote liver function, help lower inflammation, support gallbladder health, and may improve metabolic imbalances such as insulin resistance linked to an increased risk of diabetes. 

3. Can you take milk thistle every day?

Yes, you can take milk thistle every day. Milk thistle has been found safe and is generally well tolerated by most people when taken in appropriate doses.

4. Does milk thistle cleanse the liver?

While milk thistle itself doesn’t cleanse the liver, it does support liver function, stimulates the regeneration of liver cells, and protects the liver from potentially harmful by-products generated during the detoxification of drugs, hormones, and alcohol. 

5. Are there any downsides to taking milk thistle?

Milk thistle can cause mild digestive discomfort in sensitive individuals, and taking milk thistle supplements with foods generally minimizes gastrointestinal side effects. 

It’s also important to note that milk thistle may interact with certain prescription medications, and it’s crucial to discuss milk thistle use with a healthcare provider if you are taking antidiabetic medication, statins, immunosuppressants, or antipsychotic drugs. 

6. Who should not take milk thistle?

The safety of milk thistle during pregnancy has not yet been well established, and it's recommended that pregnant and breastfeeding mothers avoid milk thistle-containing products. 

In addition, individuals with a history of allergic reactions to Asteraceae plants such as daisies, sunflowers, or marigolds may be at increased risk of milk thistle allergy.


7. What is milk thistle?

Milk thistle is a flowering plant that belongs to the Asteraceae family and is closely related to daisies, marigolds, and dandelions.  

Milk thistle seeds are rich sources of silymarin, a potent flavonoid complex that has various health benefits, including strengthening liver cells, protecting the liver from inflammation, and supporting cardiovascular health. 

8. How do you use milk thistle?

Milk thistle supplements can be taken as pills, capsules, powders, or tinctures. 

While general recommendations suggest a milk thistle dose ranging between 200 and 400 milligrams, taken two to three times daily, it’s crucial to carefully follow the instructions of the milk thistle supplement you are planning to use.


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9186366/

  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7140758/ 

  3. https://www.sciencedirect.com/science/article/pii/S1665268120301708 

  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8814827/ 

  5. https://www.tandfonline.com/doi/full/10.3109/13880209.2013.842597 

  6. https://pubmed.ncbi.nlm.nih.gov/17548793/ 

  7. https://www.nccih.nih.gov/health/milk-thistle

  8. https://www.ema.europa.eu/en/documents/herbal-monograph 

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