Currently, there is limited evidence to suggest that milk thistle is effective for any of its uses.
Reported side effects from milk thistle use include bloating, diarrhea, gas, nausea and upset stomach. However, they do not appear to be common.
Milk thistle can produce allergic reactions, which tend to be more common among people who are allergic to plants in the same family (for example, ragweed, chrysanthemum, marigold, and daisy).
Milk thistle may lower blood sugar levels. People who have diabetes or hypoglycemia, or who are taking drugs or supplements that affect blood sugar levels, should use caution.
Milk thistle may also affect estrogen levels. Before taking milk thistle, let your health care provider know if you have any hormone sensitive cancers or conditions, such as breast cancer, endometriosis, or uterine fibroids.
Milk thistle may interact with the following medications:
- ledipasvir
- morphine
- raloxifene
- sirolimus
- sofosbuvir
- tamoxifen
- warfarin
Consult your physician prior to using milk thistle if you are pregnant.
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.