The liver supports many critical physiological processes in the human body, including:
- Blood volume regulation
- Breakdown of foreign chemicals and toxic compounds
- Fat and cholesterol metabolism
- Hormonal control of growth signaling pathways
- Immune system support
- Macronutrient metabolism
- Protein and amino acid metabolism (9)
Because of this diverse list of physiological functions, liver damage or illness can be extremely dangerous to health. There are many different types of liver diseases, including:
- Cancer
- Cirrhosis and fatty liver disease
- Hepatitis A, B, and C
- Non-alcoholic fatty liver disease
- Wilson disease (6)
Milk thistle extract (Silybum marianum) is commonly used to help protect the liver against toxins and reduce the risk of the aforementioned chronic liver diseases, with research suggesting it has anti-cancer, anti-diabetic, and cardioprotective effects. (8) Milk thistle extract also had antioxidant effects that may help decrease inflammation and protect the liver from damage. (7) However, to get the most benefit from milk thistle extract, it is important to choose the right form.
Research demonstrates that milk thistle has liver-protective properties.
Best milk thistle supplement
Milk thistle has been used medicinally for thousands of years and its bioactive compound, silybin, has been studied extensively for its ability to support liver health. (2) However, research also indicates that when taken orally, silybin from milk thistle extract is not well absorbed. (3) Silybin’s bioavailability can be improved significantly by combining milk thistle extract with phosphatidylcholine to create a milk thistle phytosome. (2)
Milk thistle phytosome
Phytosome technology envelops the herb to create a cell-like structure that can effectively deliver the plant and its active compounds through the gut protecting it from destruction by gastric secretions and gut bacteria, which enhances the bioavailability of the plant. In addition to enhanced absorption, the phosphatidylcholine in the phytosome is also hepatoprotective, offering a synergistic effect when combined with milk thistle. (1)
According to a 2019 prospective, blinded, two-way crossover study featuring 23 healthy volunteers, silybin phytosome demonstrated superior bioavailability compared to a non-phytosome silymarin extract. (4)
Milk thistle extract may also exert antioxidant effects that may help decrease inflammation and protect the liver from damage.
What to look for when buying milk thistle
To ensure you choose the best milk thistle supplement with the highest bioavailability possible, be sure the label indicates that the herb has been combined with phosphatidylcholine to create a phytosome. In the form of a dietary supplement, the product can be called milk thistle phytosome, silymarin phytosome, or silybin phytosome.
In addition to milk thistle, phytosome technology is used with other herbs such as Ginkgo biloba, grape seed, hawthorn, and others to enhance absorption of the active compounds found in these plants. (1)
Standardization is a way to ensure that the product has the highest percentage possible of the active compounds found in the plant. Standardized milk thistle phytosome is generally well tolerated with many of the studies featuring a product standardized to contain 70 to 80% silymarin. (5)
The bottom line
Milk thistle extract is a powerful supplement that can benefit health, especially liver health. The key to choosing the best milk thistle supplement is to look for a standardized silymarin phytosome.
If you are interested in taking a milk thistle extract, consider talking with an integrative healthcare practitioner for additional guidance.
- Bhattacharya, S. (2009). Phytosomes: the new technology for enhancement of bioavailability of botanicals and nutraceuticals. International Journal of Health Research, 2(3), 225-232.
- Bijak, M. (2017). Silybin, a major bioactive component of milk thistle (Silybum marianum L. gaernt.)—chemistry, bioavailability, and metabolism. Molecules, 22(11), 1942.
- Kidd, P., & Head, K. (2005). A review of the bioavailability and clinical efficacy of milk thistle phytosome: a silybin-phosphatidylcholine complex (Siliphos). Altern Med Rev, 10(3), 193-203.
- Mendez-Sanchez, N., Dibildox-Martinez, M., Sosa-Noguera, J., Sanchez-Medal, R., & Flores-Murrieta, F. J. (2019). Superior silybin bioavailability of silybin-phosphatidylcholine complex in oily-medium soft-gel capsules versus conventional silymarin tablets in healthy volunteers. BMC Pharmacology and Toxicology, 20(5).
- Rainone, F. (2005). Milk thistle. American Family Physician, 72(7), 1285-1288.
- Sharma, A., & Nagalli, S. (2021). Chronic liver disease. StatPearls, July 5. https://www.ncbi.nlm.nih.gov/books/NBK554597/
- Surai, P. F. (2015). Silymarin as a natural antioxidant: an overview of the current evidence and perspectives. Antioxidants, 4(1), 204-247.
- Tamayo, C., & Diamond, S. (2007). Review of clinical trials evaluating safety and efficacy of milk thistle (Silybum marianum gaertn.). Integrative Cancer Therapies, 6(2), 146-157.
- Trefts, E., Gannon, M., & Wasserman, D. H. (2017). The liver. Curr Biol, 27(21).