Milk thistle

Common name: Milk thistle
Other names: Silybum, holy thistle, Lady’s thistle, Marion thistle, St. Mary’s thistle
Latin name: Silybum marianum
Affinity: Digestive system
Actions: Cholagogue, galactogogue, demulcent, liver protector
Specific indications: Swollen painful liver or gallbladder, constipation, to increase flow of milk, liver damage from alcoholism
Diseases: Chemotherapy associated hepatoxicity(1), type II diabetes(1), cirrhosis(1), inflammation of gall bladder and duct(3), liver damage and toxicity(2), fatty liver(3), chronic hepatitis A/ B(3), high cholesterol(2), gallstones(3)
Parts used: Seeds
Energetics: Cooling, drying


Characteristics: Milk thistle is an annual weedy plant found in rocky soils in western and southern Europe and North Africa (Kuhn and Winston, 2000). It grows 2 to 4 feet high and has dark shiny green leaves with white veins. It has purple spiny flower heads that bloom from June to August.

History: Milk thistle was recognised long ago by the herbalists of old for its value as a liver tonic (Castleman, 2001). In the 1st century the Roman physician Pliny wrote that the juice of the herb helped ‘carry off bile’. The 17th century herbalist, Nicholas Culpeper recommended milk thistle for jaundice and the yellowing of the skin and eyes caused by liver disease. Later, Americas 19th century Eclectic physicians prescribed milk thistle to treat liver disorders and also, varicose veins, menstrual complaints, and kidney problems.

Current applications: David Hoffman in, Holistic Herbal, mentions, milk thistle is an excellent promoter of milk secretion, he also recommends it to increase the secretion and flow of bile from the liver and gall-bladder (Hoffman, 1988). Winston and Kuhn recommend it in the treatment of, gallstones, hepatitis A and B, mushroom poisoning, high cholesterol, and cirrhosis (Kuhn and Winston, 2000). Matthew Wood mentions, the sweet oily seed indicates that milk thistle will be suited to dry cases. Meaning that dry skin, hard, swollen, knotty veins, and constipation with dry, hard stool are often present (Wood, 2011). His specific indications include; a sore swollen liver or gallbladder and liver damage from alcoholism.

Science: Silymarin is the name for the active compounds in milk thistle, silibinin, silidaianin, and silichristin (Ferenci et al., 1989). It has been shown to protect animals against various chemical hepatotoxins. Silymarin and silibinin has been shown to display anti-cancer activity ex vivo and in vivo (Davis-Searles et al., 2005). Silibinin has notable anti-inflammatory effects ex vivo (Trappoliere et al., 2009). There is evidence in animal models that milk thistle reduces high blood cholesterol (Krečman et al., 1998).

In a double blind human study, it was effective against reducing mortality of individuals suffering with cirrhosis or damage to the liver, and was particularly effective against alcoholic cirrhosis (Ferenci et al., 1989). There are also other well controlled human trials which demonstrate milk thistle, standardised to contain a certain percentage of silymarin, is effective in reducing liver toxicity associated with chemotherapy (Ladas et al., 2010), and improving the glycemic profile of patients with type II diabetes (Huseini et al., 2006). However, the ability of milk thistle to benefit hepatitis is under question (Fried et al., 2012; Rambaldi et al., 2007).

Safety: Milk thistle is very safe to take whilst pregnant or breastfeeding and it may be used with much benefit by people of all ages.

Dosage: 5-60 drops of tincture 2-3 times daily.

Scientific Summary

Research on models

Anti-inflammatory activity: One study found that silibinin, a component of silymarin, displayed anti-inflammatory activity on human stellate cells (Trappoliere et al., 2009).

Anti-cancer: The milk thistle compounds silibinin and silymarin possess anticancer actions on human prostate carcinoma in vitro and in vivo (Davis-Searles et al., 2005). In this study, silymarin and silibinin were shown to suppress the activity of the DNA topoisomerase in DU145 cells and, among the pure compounds, isosilybin B was the most effective anti-tumour agent.

Anticholesterolemic activity: A study found antioxidant flavonolignans from milk thistle and silybin to inhibit diet-induced hypercholesterolemia the rats were fed high cholesterol diet (Krečman et al., 1998).

Research on humans

Chemotherapy associated hepatoxicity: A study (n=50, double blind placebo controlled) found in a group of children with acute lymphoblastic leukemia treatment with milk thistle with chemotherapy resulted in a near significant trend towards reduced liver toxicity after 56 days (Ladas et al., 2010). Dosage varied depending on body weight from 240mg/day to 960mg/day.

Type II diabetes: One study (n=51, double blind placebo controlled) found milk thistle treatment of type II diabetic patients for 4 months had a beneficial effect on improving the patients glycemic profile (Huseini et al., 2006). Dose was a 200mg tablet three time daily.

Cirrhosis: A study (n=170, double blind placebo controlled) found 140mg of silymarin taken three times daily reduced the mortality of patients with cirrhosis, and this effect was more pronounced in individuals with alcoholic cirrhosis (Ferenci et al., 1989).


Castleman, Michael. “The new healing herbs.” Bantam Book, New York (2001): 465-471.

Davis-Searles, Paula R., et al. “Milk thistle and prostate cancer: differential effects of pure flavonolignans from Silybum marianum on antiproliferative end points in human prostate carcinoma cells.” Cancer research 65.10 (2005): 4448-4457.

Ferenci, P., et al. “Randomized controlled trial of silymarin treatment in patients with cirrhosis of the liver.” Journal of hepatology 9.1 (1989): 105-113.

Hoffman, David. Holistic herbal. Element Books, 1988.

Huseini, H. Fallah, et al. “The efficacy of Silybum marianum (L.) Gaertn.(silymarin) in the treatment of type II diabetes: a randomized, double‐blind, placebo‐controlled, clinical trial.” Phytotherapy research 20.12 (2006): 1036-1039.

Krečman, V., et al. “Silymarin inhibits the development of diet-induced hypercholesterolemia in rats.” Planta medica 64.02 (1998): 138-142.

Fried, Michael W., et al. “Effect of silymarin (milk thistle) on liver disease in patients with chronic hepatitis C unsuccessfully treated with interferon therapy: a randomized controlled trial.” Jama 308.3 (2012): 274-282.

Kuhn, Merrily A., and David Winston. Herbal therapy and supplements: a scientific and traditional approach. Lippincott Williams & Wilkins, 2000.

Ladas, Elena J., et al. “A randomized, controlled, double‐blind, pilot study of milk thistle for the treatment of hepatotoxicity in childhood acute lymphoblastic leukemia (ALL).” Cancer 116.2 (2010): 506-513.

Rambaldi, Andrea, Bradly P. Jacobs, and Christian Gluud. “Milk thistle for alcoholic and/or hepatitis B or C virus liver diseases.” The Cochrane Library (2007).

Trappoliere, Marco, et al. “Silybin, a component of sylimarin, exerts anti-inflammatory and anti-fibrogenic effects on human hepatic stellate cells.” Journal of hepatology 50.6 (2009): 1102-1111.

Wood, Matthew. The Earthwise Herbal, Volume I: A Complete Guide to Old World Medicinal Plants. North Atlantic Books, 2011.