Milk Thistle: Uses & Benefits

Milk thistle (Silybum marianum) has a long history of use in herbal medicine, dating back over 2,000 years. It is most commonly recognised for its role in supporting liver function. The plant is easily identified by its spiky leaves, marked with distinctive white veins; its seeds are the primary source of medicinal compounds.

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In the UK, milk thistle is recognised as a traditional herbal remedy. It is licensed to ease symptoms linked to occasional overindulgence in food and alcohol, such as indigestion and stomach discomfort.

What does milk thistle do?

The seeds of milk thistle contain silymarin, a complex of antioxidant compounds. These antioxidants help protect the body’s cells from damage caused by free radicals – unstable oxygen-containing molecules. In the liver, silymarin may help shield cells from toxins, including those from excessive alcohol intake.

Milk thistle appears to work by maintaining or boosting the liver’s own protective antioxidant, glutathione, and protecting liver cell membranes from toxins. Additionally, it may stimulate the regeneration of liver cells, supporting overall liver health.

What is milk thistle good for?

Liver support

Studies indicate that milk thistle can enhance liver function. A case study on reducing liver enzyme levels in non-alcoholic fatty liver disease showed that after silymarin (milk thistle extract) at a dosage of 140 mg twice daily, liver enzymes decreased significantly, indicating improved liver function. This aligns with broader evidence suggesting that milk thistle has antioxidant and hepatoprotective properties beneficial in the context of fatty liver disease. Research involving 19 clinical trials on alcoholic liver disease also found that silymarin reduced the level of one specific liver enzyme. Participants taking milk thistle extracts showed improved survival rates both overall and when taking liver-related mortality into account.

Type 2 Diabetes

Milk thistle may also benefit blood sugar control in people with type 2 diabetes. One study reported that consuming 140mg of silymarin three times daily for 45 days significantly improved fasting blood glucose levels by 11% and improved insulin resistance. Silymarin’s antioxidant action may reduce oxidative stress that impairs insulin signalling. Total and LDL cholesterol fell by over 7% and blood triglycerides dropped by 23%, while HDL cholesterol (‘good’ cholesterol) increased.

How much milk thistle should I take per day?

A typical milk thistle dose is equivalent to 108mg of silymarin (ranging from 193–261mg of dry extract), taken once or twice daily.

When is the best time to take milk thistle?

For optimal absorption, it is usually best to take it between meals.

How long should I take milk thistle to detox my liver?

If you’re considering milk thistle for liver support, most evidence-based uses involve daily supplementation for at least 8–12 weeks or longer, depending on your health status and goals. It should be viewed as a supportive therapy over time, rather than a quick fix.

If you have a medical condition or are taking any prescribed medicines, talk to your doctor before taking any herbal medicine.