The power of milk thistle

And its many medicinal applications

Milk thistle (Silybum marianum) is a weed originally found throughout Europe and it now grows worldwide, including in North America and Asia. The plant’s name originates from the white blotches on its otherwise green leaves and the milky white liquid sap that comes from the plant’s leaves when they are crushed. Milk thistle has enjoyed a long history of use as a medicinal plant. References to its use can be found dating back to the first century. Milk thistle is consistently one of the top-selling medicinal herbs worldwide and has been steadily gaining popularity both with consumers and researchers to treat a multitude of conditions.


Milk thistle is commonly sold in capsules, tablets, liquid extracts, powders, and teas. The leaves and stems are active, but the most therapeutically active part of the plant is the seed. Milk thistle is a well-studied plant (almost 1,000 referenced papers) and because of this we know a great deal about its active components. The primary active components are a class of flavonoid (antioxidant) compounds found in the seeds, collectively referred to as silymarin.


Silymarin is a mixture that contains several closely related compounds, including silybin (consisting of the silybins A and B), isosilybin (consisting of the isosilybins A and B), silychristin and isosilychristin, silydianin, and taxifolin. Silymarin exhibits strong antioxidant and anti-inflammatory activities. Silibinin makes up 50%-70% of silymarin and has been shown in clinical studies to be the most biologically active and beneficial constituent of milk thistle. For ideal therapeutic benefit, it is recommended to use concentrated standardized extracts (capsules, tablets or liquids).


Milk thistle’s medicinal history shows uninterrupted use for over 2,000 years as a safe natural remedy for a variety of ailments such as liver, kidney, and gall bladder problems, mushroom poisoning and snake bites. Today, milk thistle is used frequently to help in the prevention and treatment of:


Liver Problems:

Liver disease can be due to inherited (genetic) factors, caused by lifestyle or a combination of the two. A variety of factors that damage the liver, such as viral infections (hepatitis B and C viruses), autoimmune diseases, alcohol use (and overuse) and obesity are common lifestyle culprits. Over time, damage to the liver results in scarring (cirrhosis), which leads to liver failure, a fatal condition. Milk thistle has been extensively studied for various hepatic disorders. Silymarin and silybin may protect the liver against damage from toxic chemicals by blocking toxins from entering cells or by moving toxins out of cells before damage can occur. Its use both historically and currently has been shown to be safe and well tolerated. More research is needed to evaluate the real biological pathways and mechanisms of silymarin in the treatment of liver diseases.


Where milk thistle shines is in the area of liver support. Many people use milk thistle to strengthen the liver and to keep it healthy. With continual exposure to thousands of toxins daily (all of us in the industrialized world) the liver can become overworked and prone to disease. Milk thistle’s silymarin supports liver health and function.


  1. Bile – The liver produces bile liquid to break down fats in the small intestine during digestion. Milk thistle helps increase bile production thus improving fat metabolism and potentially even reducing the risk of heart disease if taken regularly.

  2. Inflammation- Silymarin is a potent anti-inflammatory antioxidant. It helps prevent liver inflammation caused by excessive fat consumption.

  3. Regeneration- Silymarin enhances liver regeneration (healing and repair) both from regular daily damage and from damage caused by injury or toxicity.



Milk thistle has also demonstrated promising protection against diabetes and diabetes-related complications, including damage to the kidneys and blood vessels. Milk thistle has been shown to improve results from conventional diabetes treatment. It helps to lower blood sugar levels, and improves cholesterol profile. Researchers also have found that milk thistle improved insulin resistance, a key characteristic of type 2 diabetes. As diabetes is so prominent in Western society, this is a hotbed of research and we expect to hear a fair bit in the coming years, pinpointing specifically milk thistle’s mechanism of action and its potential as a therapeutic aid in diabetes.


Gallstones and the Gallbladder:

Preliminary studies suggest that silymarin may protect against gallbladder stone formation by reducing cholesterol output in the bile and by expanding the bile acid pool. The herb does soften gallbladder tissues, increases bile flow, and reduces inflammation. There is an important warning here, however: if you suspect that you already have gallstones, avoid using milk thistle until you can consult with a practitioner to determine their size and number. This is because milk thistle acts as a demulcent, able to promote clearing of any stagnation in the gallbladder. However, some stones may be too large to pass through the organ’s passages.



Laboratory research suggests that silymarin and more specifically its component silibinin, from milk thistle may have broad anti-cancer effects. Milk thistle has the potential to make chemotherapy less toxic and more effective. Silbin has been shown to significantly reduce growth of multiple cancer cell types and promote cancer cell apoptosis (destruction). However these studies are preliminary and were performed in vitro. More research needs to be done before we can make definitive conclusions.


Milk thistle is an ancient remedy for our modern world. It helps to protect our liver from the damage our daily lives (and poor choices) create as well as helping to limit the damage caused from diabetes, gallstones and possibly cancer. Adding it to your daily health regimen may just be the little health kick you need to move up to the next level.


Please remember that milk thistle works with conventional therapies, so do not replace conventional therapies or prescribed medicines without consulting your practitioner.


Joel Thuna, MH, is a master herbalist with over 30 years of experience. Dr. Claude Gallant holds a PhD in Microbiology.

Categories: Supplements, Neutraceuticals, & Herbs