Milk thistle is a plant that contains silymarin, a substance that some people take to help with liver function, diabetes, indigestion, and other conditions. It has been widely used in Europe, where it is a common complementary treatment for liver problems such as hepatitis and cirrhosis. In Canada, it is sold as a natural health product.
Why It Is Used
There isn't clear evidence from science that taking milk thistle as a natural health product helps with liver problems, such as hepatitis, cirrhosis, and inflammation of the bile ducts (cholangitis).
Milk thistle may cause nausea, diarrhea, bloating, pain, or allergies.
The Natural and Non-Prescription Health Products Directorate (NNHPD), within the Health Products and Food Branch of Health Canada, regulates natural health products in Canada. Natural health products, including milk thistle, must be reviewed and approved by the NNHPD before they can be sold in Canada.
Always tell your doctor if you are using a natural health product or if you are thinking about combining a natural health product with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a natural health product. This is especially important for women who are pregnant or breastfeeding.
When using natural health products, keep in mind the following:
- Like conventional medicines, natural health products may cause side effects, trigger allergic reactions, or interact with prescription and non-prescription medicines or other natural health products you might be taking. A side effect or interaction with another medicine or natural health product may make other health conditions worse.
- Natural health products may not be standardized in their manufacturing. This means that how well they work or any side effects they cause may differ among brands or even within different lots of the same brand. The form you buy in health food or grocery stores may not be the same as the form used in research.
- Other than in vitamins and minerals, the long-term effects of most natural health products are not known.
Current as of: January 3, 2022
Author: Healthwise Staff
Adam Husney MD - Family Medicine
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