In most clinical trials, the incidence of adverse reactions was approximately equal in milk thistle and control groups.Zhu 2018 The US Agency for Healthcare Research and Quality and the German Commission E reported no serious adverse events associated with milk thistle within the recommended dosage range.Post-White 2007, Rainone 2005.
Avoid use of the aboveground parts of the plant in women with hormone-sensitive conditions (eg, breast, uterine, and ovarian cancers; endometriosis; uterine fibroids), unless under the supervision of a physician, due to the extract's possible estrogenic effects. The more commonly used milk thistle seed extracts are not known to have estrogenic effects.Kidd 2005.
Despite the positive findings, subsequent studies have been unable to replicate the results or demonstrate that milk thistle prescribed on its own would render the same effects.
According to a comprehensive review of studies in the American Journal of Gastroenterology, milk thistle neither improves liver function nor reduces the risk of death in people with alcoholic liver disease, hepatitis B, or hepatitis C.
In another case, doctors reported further success administering high doses of silibinin intravenously. The milk thistle compound prevented hepatitis C reinfection in their liver graft transplant patient. (137)
In patients with hepatitis C, beneficial effects have not been noted with use of silymarin. In a multicenter, double-blind, placebo-controlled trial, 154 patients with chronic hepatitis C and elevated ALT levels who were unsuccessfully treated with interferon, silymarin 420 mg or 700 mg 3 times daily for 24 weeks did not significantly reduce ALT levels.Fried 2012 In a study of children 5 to 16 years of age with nonalcoholic fatty liver disease, silymarin given for 12 weeks improved fatty liver infiltration, liver function tests, and triglyceride levels; however, LDL and HDL cholesterol levels were not altered.Famouri 2017.
Boosts Antioxidant Activity: It is particularly useful for increasing production of glutathione—a powerful antioxidant produced by the body, as well as increasing the levels of other antioxidants, such as superoxide dismutase.
In a rat model of hereditary hypertriglyceridemia, 4 weeks of silymarin administration significantly reduced triglyceride and total cholesterol levels, and increased high-density lipoprotein (HDL) cholesterol levels.Poruba 2015.