Possible side effects
According to the NIH, milk thistle supplements do not have any serious side effects. However, on very rare instances it may cause:
- nausea [11]
- a laxative effect
- upset stomach
- heartburn
- a mild allergic reaction, at high doses
There is not much information about the interaction of milk thistle with other drugs, including anticancer medications and radiation therapy [12]. It is best to discuss with your doctor before you start any new supplement or medication.