{"entity":{"id":"milk-thistle-silymarin","kind":"technology","name":"Milk thistle (silymarin)","aka":["Silymarin","Silibinin","Silybum marianum","Holy thistle","Mary thistle"],"tldr":"Milk thistle is a herb taken to protect the liver, and many people use it during chemotherapy for that reason. Small studies hint that it may ease some liver and nerve side effects, but none is large enough to rely on, and it can change how some medicines are handled by the body.","summary":"Silymarin, the flavonolignan mixture extracted from milk thistle seed, is used mainly for liver disease. Memorial Sloan Kettering's About Herbs summary describes small studies suggesting less chemotherapy liver toxicity in children with acute lymphoblastic leukaemia and in women with non-metastatic breast cancer, less chemotherapy neuropathy and hand-foot syndrome, and less radiation mucositis in head and neck cancer; none of these is a large trial. In chronic hepatitis C, a large survey and a multicentre trial found that silymarin did not lower liver enzymes, which is a caution against assuming it protects the liver in general. The NCI PDQ summary, no longer being updated, reached the same view: laboratory activity, few side effects, and little information about interactions with anticancer drugs or radiotherapy. MSK lists interactions to tell the team about: milk thistle can inhibit the liver enzyme CYP3A4 in some studies (others found no effect), can modulate UGT enzymes, may slow clearance of sirolimus, was linked to seven cases of pancreatitis with haloperidol or risperidone, and in one case report a liver-cleanse product containing it raised the warfarin INR from 2.64 to 4.12. High doses can raise bilirubin and liver enzymes. Laboratory work showing that silibinin acts on oestrogen receptor beta is a reason for people with hormone-sensitive cancers to ask before taking it.","status":"phase-2","asOf":"2026-11-04","links":[{"label":"MSK About Herbs: Milk thistle (page last updated 22 July 2026)","url":"https://www.mskcc.org/cancer-care/integrative-medicine/herbs/milk-thistle"},{"label":"NCI PDQ: Milk thistle","url":"https://www.cancer.gov/about-cancer/treatment/cam/hp/milk-thistle-pdq"}],"tags":["complementary","supportive-care","evidence:insufficient"],"related":["black-cohosh","coenzyme-q10"],"cancers":[],"sections":["supportive-care","chemotherapy","nutrition-lifestyle"],"technologies":["integrative-oncology","dietary-supplements-treatment-interactions"],"targets":[],"drugs":["sirolimus"],"companies":[],"institutions":[],"pathways":[],"terms":["hepatotoxicity"],"trials":[],"people":[],"bottlenecks":["b-toxicity-qol"],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"principle":"Silymarin and silibinin are antioxidant flavonolignans that stabilise liver-cell membranes and stimulate detoxifying enzymes in laboratory models; anticancer effects are shown only in cells and animals.","strengths":["Generally well tolerated at usual doses","Small studies in childhood leukaemia and breast cancer suggest less liver toxicity"],"limitations":["No adequately sized trial in people with cancer","Possible interactions through CYP3A4 and UGT enzymes","Did not lower liver enzymes in a multicentre hepatitis C trial"]},"route":"/technologies/milk-thistle-silymarin/","neighbours":{"technology":[{"id":"aloe-vera","kind":"technology","name":"Aloe vera","route":"/technologies/aloe-vera/"},{"id":"black-cohosh","kind":"technology","name":"Black cohosh","route":"/technologies/black-cohosh/"},{"id":"coenzyme-q10","kind":"technology","name":"Coenzyme Q10","route":"/technologies/coenzyme-q10/"},{"id":"dietary-supplements-treatment-interactions","kind":"technology","name":"Dietary supplements during cancer treatment: interactions and harms","route":"/technologies/dietary-supplements-treatment-interactions/"},{"id":"integrative-oncology","kind":"technology","name":"Evidence-based integrative oncology","route":"/technologies/integrative-oncology/"}],"section":[{"id":"chemotherapy","kind":"section","name":"Chemotherapy","route":"/fronts/chemotherapy/"},{"id":"nutrition-lifestyle","kind":"section","name":"Diet, Exercise & Lifestyle","route":"/fronts/nutrition-lifestyle/"},{"id":"supportive-care","kind":"section","name":"Supportive Care & Survivorship","route":"/fronts/supportive-care/"}],"drug":[{"id":"sirolimus","kind":"drug","name":"Sirolimus","route":"/drugs/sirolimus/"}],"term":[{"id":"hepatotoxicity","kind":"term","name":"Hepatotoxicity (liver enzyme elevation)","route":"/terms/hepatotoxicity/"}],"bottleneck":[{"id":"b-toxicity-qol","kind":"bottleneck","name":"Toxicity and quality of life are undervalued","route":"/bottlenecks/b-toxicity-qol/"}]}}