What are the possible side effects of Milk Thistle (Silybum marianum)?
Milk thistle appears to be well tolerated in recommended doses for up to six years. Some patients in studies have experienced stomach upset, headache, and itching. There are rare reports of appetite loss, gas, heartburn, diarrhea, joint pain, and impotence with milk thistle use. One person experienced sweating, nausea, stomach pain, diarrhea, vomiting, weakness and collapse after taking milk thistle. This reaction may have been due to an allergic reaction, and improved after 24 hours. High liver enzyme levels in one person taking milk thistle returned to normal after the person stopped taking the herb. In theory, milk thistle may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugars. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary. Theoretically, because milk thistle plant extract might have estrogenic effects, w