Milk thistle, known scientifically as Silybum marianum, is primarily composed of a group of compounds collectively called silymarin. Silymarin itself contains several related compounds, including silybin (also called silibinin), isosilybin, silychristin, and silydianin. These are flavonolignans, which are believed to be the active components that contribute to milk thistle’s liver-protecting properties.

In addition to these active compounds, milk thistle supplements may also contain other ingredients, depending on the product formulation. These can include:

  • Fillers and Binders: Substances like cellulose or magnesium stearate might be used to give form to the tablet or capsule.
  • Coating Agents: Some supplements might have a coating to make them easier to swallow.
  • Stabilizers and Preservatives: To maintain the shelf life of the supplement.
  • Additional Herbs or Nutrients: Some formulations include additional herbs or nutrients designed to complement the effects of milk thistle.
  • It’s important to read the label of any milk thistle product to understand exactly what ingredients are included, especially if you have allergies or sensitivities.