- Milk thistle has been used medicinally for over 2,000 years, most commonly for the treatment of liver and gallbladder disorders. A flavonoid complex called silymarin can be extracted from the seeds of milk thistle and is believed to be the biologically active component. The terms "milk thistle" and "silymarin" are often used interchangeably.
- Milk thistle products are popular in Europe and the United States for various types of liver disease. Although numerous human trials have been published, most studies have not been well designed or reported.