Is Milk Thistle Safe?
If you are thinking about taking milk thistle, safety precautions of the supplement should be reviewed with your healthcare provider. For example, you may not be able to use it safely if you have cancer, endometriosis, or uterine fibroids. Milk thistle may have estrogen-like effects, which can make certain conditions that are sensitive to estrogen worse. Milk thistle safety precautions also apply to people with certain allergies.
An Overview of Milk Thistle SafetyMilk thistle is a popular dietary supplement used for treating liver diseases, as well as a variety of other conditions. However, you should talk with your healthcare provider prior to taking milk thistle if you have:
- Any chronic medical condition
- Cancer (or a history of cancer)
- Uterine fibroids
- Any allergies, including allergies to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant
You should also make sure to tell your healthcare provider about any other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
Specific Milk Thistle Safety Warnings and Precautions
Some warnings and precautions to be aware of concerning the safety of milk thistle include the following:
- As dietary supplements, milk thistle supplements are not as closely regulated as prescription (or non-prescription) drugs. They can be marketed without any proof that they are either safe or effective. Do not assume that just because a product is sold or advertised in the United States that it is safe or effective (or even that it contains the right ingredients in the right amounts). Be sure to look for milk thistle supplements from a reputable manufacturer. Your pharmacist is a good resource for information about which manufacturers are the most reputable.
- Milk thistle may have estrogen-like properties and could, theoretically, stimulate some cancers (especially estrogen-sensitive cancers, such as breast cancer). If you have cancer (or have ever had cancer), do not take milk thistle without checking with your healthcare provider.
- Because milk thistle may have estrogen-like properties, there is some concern that it can worsen conditions that are sensitive to estrogen (such as endometriosis or uterine fibroids). Make sure to check with your healthcare provider before taking milk thistle if you have one of these conditions, as you may need to be monitored more closely (and you may have to stop taking milk thistle, if your condition worsens).
- It is not known if milk thistle is safe for pregnant or breastfeeding women (see Milk Thistle and Pregnancy and Milk Thistle and Breastfeeding).
- Milk thistle is a plant that is related to daisies, ragweed, chrysanthemums, and marigolds. People allergic to these plants may also be allergic to milk thistle products.