Milk thistle (Silybum marianum) is a plant native to the Mediterranean, known for its powerful compound silymarin found in the seeds. It is packed with antioxidants that may help support healthy liver function.
Milk thistle supplements might improve your liver health, especially if you've been exposed to toxins or have a history of alcohol use. These supplements could also help support healthy metabolism, reduce inflammation, and protect cells from damage.
In this blog post, we have highlighted the 10 best milk thistle supplements in 2025. We have also covered the potential side effects and pros and cons of these products.
According to the makers, Now Foods Milk Thistle Extract provides around 300 mg of milk thistle extract per capsule, standardized to 240 mg of silymarin flavonoids. The makers state that Now Foods Milk Thistle Extract also includes dandelion root and artichoke leaf, which might support your digestive health and bile production. These potent ingredients may also help enhance your body's natural detoxification processes.
Nutricost claims that their Milk Thistle provides a concentrated 4:1 extract of milk thistle seed, with each capsule containing 250mg, equivalent to 1,000mg of raw herb. It could help your body's natural detoxification processes.
As per the official website, Nutricost Milk Thistle is third-party tested and made in a GMP-compliant, FDA-registered facility. It is said to use plant-based capsules, rice flour, and vegetable-sourced magnesium stearate, ensuring the supplement is free from unnecessary additives.
According to its official website, Nature's Bounty Milk Thistle provides 250 mg of standardized seed extract per capsule. It could also support liver cell maintenance and detoxification processes.
Oxidative stress caused by free radicals could negatively impact cellular health, particularly in the liver. Nature's Bounty claims that their Milk Thistle formula may help neutralize these free radicals, which could support your body's natural detox pathways and help maintain liver resilience. Nature's Bounty Milk Thistle comes in a 200-capsule bottle, and the makers recommend taking one capsule three times daily, preferably with meals.
According to the official website, Horbäach Milk Thistle is made with pure seed extract. It is said to deliver around 3,000 mg of milk thistle seed per serving of three capsules, sourced from a concentrated 4:1 extract. Horbäach Milk Thistle may contribute to maintaining healthy liver function by supporting the body's ability to regenerate liver tissue and filter toxins more effectively. It is also free from yeast, milk, gluten, wheat, lactose, and soy.
Vimergy Milk Thistle is a liquid extract that may support liver health and promote healthy digestion. It provides the equivalent of 2200mg of fresh milk thistle through a concentrated 20:1 formula per serving of 2ml.
As per the official website, Vimergy Milk Thistle may support liver cell protection and help reduce oxidative stress. It could also promote bile production, which supports fat metabolism and enhances nutrient absorption to maintain digestive health.
The makers state that Vimergy Milk Thistle is USDA Certified Organic, non-GMO, and free from citric acid, maltodextrin, soy, corn, alcohol, sugar, and preservatives. It comes in a 115mL bottle with 57 servings and could be easily mixed with water, juice, or smoothies as part of your daily routine.
As per the official website, Zazzee Naturals Organic Milk Thistle features a 30:1 extract, providing the equivalent of 7,500 mg of raw milk thistle in each capsule. This concentrated formulation is standardized to 80% silymarin flavonoids, which may support liver cell regeneration, reduce oxidative stress, and aid in detoxification.
The makers state that Zazzee Milk Thistle is USDA Organic certified and meets strict standards for sourcing and purity. The formula also includes an Organic Stabilizer Blend, which combines Organic Gum Arabic, Organic Rice Extract, Organic Rice Hulls, and Organic Sunflower Oil.
FarmHaven USDA Organic Milk Thistle provides 375 mg of organic milk thistle seed extract per capsule. Standardized to 80% silymarin and concentrated at a 30:1 ratio, each FarmHaven USDA Organic Milk Thistle capsule offers the equivalent of 11,250 mg of raw milk thistle. This high concentration of silymarin may support your liver by promoting detoxification and protecting liver cells. As per the makers, FarmHaven USDA Organic Milk Thistle may help detoxify your body, regulate blood sugar, and support immune function.
OmniBiotics Milk Thistle provides a high-potency 1500 mg dose of organic milk thistle seed extract per capsule, utilizing a 4:1 concentration ratio. This enhanced concentration may support better bioavailability. As per the official website, one bottle of OmniBiotics Milk Thistle contains 120 vegetarian capsules, and the formula is certified organic by CCOF, ensuring that all ingredients are derived from high-quality, U.S.-sourced plants.
Metagenics Milk Thistle Extract could help neutralize free radicals to reduce oxidative stress, preventing toxins from binding to liver cells and supporting liver cell regeneration by enhancing protein synthesis. As per the official website, Metagenics Milk Thistle Extract provides 56 mg of milk thistle seed extract per serving of capsule, which may help protect liver cells against environmental stressors.
Puritan's Pride claims that their Milk Thistle Extract features a concentrated 4:1 extract sourced from the seeds of Silybum marianum. They also mentioned that it could help protect liver cells from excessive oxidative stress and support liver function.
As per the official website, Puritan's Pride Milk Thistle provides 250 mg of milk thistle extract per capsule in a rapid-release format designed to promote efficient absorption. It may also help maintain liver cell membrane integrity and assist your body's natural detoxification processes.
Headaches can occasionally occur when taking milk thistle supplements due to your body adjusting to the potent compounds, like silymarin, which can affect the liver and digestive system. As milk thistle supports liver detoxification, it could cause temporary changes in metabolic processes, which in turn might lead to headaches.
Milk thistle supplements can sometimes cause skin rashes due to allergic reactions, especially in sensitive people. The active compound, silymarin, in these products has strong detoxification effects, and as it is processed and excreted by your body, it can trigger skin reactions like redness, irritation, or rashes. Symptoms of skin rashes might include itching, swelling, or hives.
Milk thistle supplements can lower blood sugar levels by improving insulin sensitivity and promoting detoxification in the liver. This is generally beneficial for people looking to manage their blood sugar levels. However, for people already on medication to control blood sugar, taking milk thistle products could lead to hypoglycemia, which can cause symptoms like dizziness, confusion, shakiness, sweating, or even fainting.
Now Foods, Nutricost, and Nature's Bounty have the strongest reputations among the brands we evaluated in this review. Now Foods holds an A+ rating from the Better Business Bureau (BBB), which shows it consistently handles customer issues well and operates with transparency.
Nutricost also has an A+ BBB rating, reflecting very few complaints and reliable customer support. Nature's Bounty matches this with its A+ rating on BBB, indicating strong business practices and responsiveness, even though it doesn't have a presence on Trustpilot.
Horbäach received an A-rating on BBB, which means it generally resolves customer concerns but may have slightly more complaints than higher-rated companies.
Vimergy, Zazzee Naturals, FarmHaven, and OmniBiotics are not rated on BBB or Trustpilot, which makes their reliability harder to verify.
FarmHaven and OmniBiotics present well-formulated products but also lack third-party reputation data to confirm customer satisfaction.
Metagenics holds a B-rating on BBB, which points to a higher number of unresolved complaints or delayed customer service responses. It also has a 2.6-star rating on Trustpilot, showing mixed experiences from users, with some mentioning experiencing mild digestive discomfort.
Puritan's Pride has a 1.5-star Trustpilot rating with 270+ reviews, the lowest among all brands reviewed, signaling consistent problems with customer service, shipping, or product quality.
Puritan's Pride offers the best value at $0.05 per serving, giving you 360 softgels for $18.89 through a buy-one-get-one-free deal. Nutricost follows closely at $0.07 per serving, with 240 servings for $16.95, making it suitable for long-term use. Nature's Bounty comes at $0.08 per serving, offering 200 capsules for $16.20 via third-party platforms like Amazon. Horbäach also delivers decent value at $0.16 per serving, with 100 servings for $16.47.
Zazzee Naturals and FarmHaven, both organic, are priced similarly at $0.23 and $0.25 per serving, respectively. Zazzee gives you 120 servings for $27.97, while FarmHaven is available at $29.99 for the same count with USDA certification.
OmniBiotics is priced at $0.29 per serving, offering 120 organic servings for $34.95, making it a higher-cost premium option. Now Foods offers only 50 capsules for $13.99 ($0.28 per serving).
Metagenics, at $0.33 per serving for 90 servings ($29.75), is marketed as a premium product but falls short on value. Vimergy ranks last in value at $0.56 per serving, offering just 57 servings for $32.00.
OmniBiotics ranks highest with a lifetime satisfaction guarantee, offering flexibility. Puritan's Pride follows closely with a 90-day return window and acceptance of opened products, making it highly risk-free. Nutricost, Zazzee Naturals, and Metagenics all offer generous 60-day money-back guarantees, giving you enough time to try their product and request a refund if needed.
Nature's Bounty also offers a 60-day guarantee but limits it to U.S. customers. Horbäach allows returns within 30 days, though it's unclear if opened products are accepted. Now Foods and FarmHaven both stick to a 30-day window and only accept unopened products, with Now Foods not covering return shipping.
Vimergy falls to the bottom with a strict 30-day policy for unopened products only unless there's a defect. Its policy offers the least flexibility, which makes it the most restrictive option.
Milk thistle supplements could help protect liver cells, support detoxification, and improve liver function. The 10 supplements discussed above include high-potency extracts and standardized silymarin content, and some of them also contain additional ingredients like dandelion or artichoke.
However, Milk Thistle supplements may also cause potential side effects like digestive discomfort, headaches, or skin reactions. In some cases, milk thistle products could also interact with medications, particularly those processed by the liver or those that can affect blood sugar levels.
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