Milk thistle is generally considered safe and well-tolerated, with very few cases of side effects reported.
The most common side effects aren’t serious and include gastrointestinal upset, such as a mild laxative effect. When taken within the recommended dose range, however, it is thought to be effective and mostly free of allergic reactions.
Milk thistle may interact with some medications, including allergy medicines, anti-anxiety drugs and blood thinners, among others. If you are taking any medications, speak with your health care provider to prevent any milk thistle interactions before starting supplementation.
It also has estrogenic effects, meaning that it mimics the effects of estrogen in the body. If you have hormone-sensitive conditions such as uterine fibroids, endometriosis or ovarian cancer, you should consult with your doctor before starting supplementation.
Also note that antioxidants like those found in milk thistle have been shown to possibly interfere with the efficacy of some cancer chemotherapy drugs by protecting cancer cells from cell death.
Finally, keep in mind that, although many holistic practitioners recommend milk thistle for dogs to help promote liver health, it’s best to talk to your vet before starting supplementation to keep your furry friends safe. *
