This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

What is the best milk thistle supplement?

The liver is one of the body’s most critical organs. It protects us from toxins that are around us — heavy metals, chemicals, preservatives and contaminants found in our food, water, air and household products. Over time these toxins, as well as alcohol, medications and protein powders, can damage and overburden your liver.

Milk thistle has been used for naturopathic healing properties for the liver and other parts of the digestive system. There is a wide variety of milk thistle supplements available in different forms and quantities. For its high potency and absorption, the best milk thistle supplement is OmniBiotics Milk Thistle Capsules.

What to know before you buy a milk thistle supplement

What is milk thistle?

Milk thistle is a flowering herb native to Mediterranean countries and related to the ragweed and daisy plant family. Silymarin, an active ingredient in milk thistle, is extracted from the plant seeds for its antioxidant properties.

What is milk thistle used for?

Milk thistle has been used historically to naturally treat symptoms of the digestive system, including the liver and gallbladder. Modern naturopathic applications include cirrhosis, gallbladder conditions, hepatitis and jaundice.

It also has been used in combination with diabetes medication to improve cholesterol in Type 2 diabetics. A National Institutes of Health study indicates that milk thistle improves insulin resistance and decreases blood sugar levels.

Before using milk thistle for any of these purposes, consult your health care provider to ensure there are no interactions with other medications or underlying conditions.

Is milk thistle good for cardiovascular health?

The ability of milk thistle to lower “bad” low-density lipoprotein cholesterol finds a modern use in combining the supplement with statins. Your health care provider should determine if milk thistle is an appropriate supplemental treatment.

What to look for in a milk thistle supplement

Silymarin concentration

Many supplements are manufactured as milk thistle seed extract, but the key to the supplement’s effectiveness is the percentage of silymarin in each dose. Silymarin is the active ingredient in milk thistle that provides health benefits. Check the manufacturer’s label for the amount of bioavailable silymarin in each tablet or liquid dose.


Milk thistle supplements are sold in three forms. Soft-gel capsules and tablets are the most common, but liquid extracts are available for people who struggle with swallowing or prefer faster absorption. All supplements should be stored in a cool, dry space.


The range of recommended doses varies widely, from 175 to 2,000 milligrams. Most dosages for liver, gallbladder and digestive disorders range from 210 to 600 milligrams of milk thistle.


Most milk thistle supplements are made without soy, gluten, eggs, nuts, dairy and other known allergies. Check the label for ingredients used in manufacturing.

How much you can expect to spend on a milk thistle supplement

Milk thistle supplement prices are based on their form and quantity. Tablets and capsules, which cost 8-38 cents per dose, are less expensive than liquid extracts, which run 33-40 cents per dose. Supplements with additional herbal ingredients cost more than milk thistle-only products.

Milk thistle supplement FAQ

Are there side effects from milk thistle supplements?

A. Since the milk thistle plant is part of the ragweed and daisy family, anyone with allergies to these plants and marigolds and chrysanthemums should be aware of potential allergic reactions. People with artichoke and kiwi allergies also should take caution.

Anyone taking antibiotics, blood thinners or cholesterol medication should consult their health care provider about potential interactions.

According to the Mayo Clinic, milk thistle can cause digestive upset, itchiness and headache. It also raises estrogen levels and should be avoided by people with breast cancer, uterine cancer and ovarian cancer.

What are the signs of a damaged liver?

A. Most damage to the liver isn’t experienced until liver disease has started. Early-stage liver disease can lead to fatigue, easy bruising, itching and right-side abdominal pain. Advanced disease symptoms are jaundiced eyes and skin, leg swelling, dark urine, pale-colored stools and abdominal pain and distention.

What is the best milk thistle supplement to buy?

Top milk thistle supplement

best OmniBiotics Milk Thistle Capsules

OmniBiotics Milk Thistle Capsules

What you need to know: These all-natural capsules contain additional silymarin extract to aid in absorption and provide maximum potency.

What you’ll love: Each capsule contains 1,500 milligrams of bioavailable milk thistle extract, intended to support the liver and gallbladder health. Certified organic, the supplement is non-GMO and free of gluten, dairy, nuts, soy, sugar and fillers.

What you should consider: A small number of consumers reported the bottles broke easily.

Where to buy: Sold by Amazon

Top milk thistle supplement for the money

best Now Foods Extra Strength Silymarin

Now Foods Extra-Strength Silymarin

What you need to know: This combination supplement of milk thistle, artichoke and dandelion supports liver and gallbladder health.

What you’ll love: With 450 milligrams of silymarin per capsule, this vegetarian formula is powerful and safe. A family-owned manufacturer makes the supplement without soy, nuts, gluten or dairy. It is kosher and non-GMO.

What you should consider: The capsules contain additional filler ingredients.

Where to buy: Sold by Amazon and iHerb

Worth checking out

best Nature’s Answer Milk Thistle Seed Extract

Nature’s Answer Milk Thistle Seed Extract

What you need to know: This is a powerful liquid supplement with a super-concentrated 2,000 milligrams of milk thistle seed extract per serving.

What you’ll love: To maximize liver support, the company promises that all botanicals are analyzed for purity and quality to ensure the highest-quality ingredients are used. The extract is non-GMO and free of alcohol and gluten.

What you should consider: A small number of reviewers reported an unpleasant taste.

Where to buy: Sold by Amazon and iHerb


Want to shop the best products at the best prices? Check out Daily Deals from BestReviews.

Sign up here to receive the BestReviews weekly newsletter for useful advice on new products and noteworthy deals.

Steve Ganger writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

Copyright 2022 BestReviews, a Nexstar company. All rights reserved.