Milk Thistle

Supplement Forms/Alternate Names:

Silymarin, silybum marianum, Mary thistle, holy thistle


Milk thistle is a spiky green plant. Silymarin is a compound found in its seeds. It has been used to lower cholesterol and improve liver function. Milk thistle can be taken as a pill, powder, or extract. It can also be applied as a cream.


150 milligrams 2 to 3 times daily

What Research Shows

Likely Effective

May Be Effective

May Not Be Effective

  • Nonalcoholic steatohepatitis —may not ease symptoms G1

Not Enough Data to Assess

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe to take milk thistle and to use it on the skin for a short time. Not enough studies have been done to say whether it is safe to use for a long period or by women who are pregnant or breastfeeding.H3


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse, such as:

  • People taking antibiotics should talk to their doctor before taking milk thistle. It may make the medicine less effective.H4
  • People taking blood thinners should talk to their doctor before taking milk thistle. It may increase the risk of bleeding.H2
  • People taking antiretroviral medicine should talk to their doctor before taking milk thistle. It may interact with the medicine.H1


A. Acute Hepatitis

A1. El-Kamary SS, Shardell MD, et al. A randomized controlled trial to assess the safety and efficacy of silymarin on symptoms, signs and biomarkers of acute hepatitis. Phytomedicine. 2009;16(5):391-400.

B. Breastfeeding Support

B1. Mortel M, Mehta SD. Systematic review of the efficacy of herbal galactogogues. J Hum Lact. 2013 May;29(2):154-162.

B2. Zecca E, Zuppa AA, et al. Efficacy of a galactogogue containing silymarin-phosphatidylserine and galega in mothers of preterm infants: a randomized controlled trial. Eur J Clin Nutr. 2016 Oct;70(10):1151-1154.

B3. Serrao F, Corsello M, et al. The Long-Term Efficacy of a Galactagogue Containing Sylimarin-Phosphatidylserine and Galega on Milk Production of Mothers of Preterm Infants. Breastfeed Med. 2018 Jan/Feb;13(1):67-69.

C. Decompensated Liver Cirrhosis

C1. May be improve quality of life. Fathalah WF, Abdel Aziz MA, Abou El Soud NH, El Raziky MES. High Dose of Silymarin in Patients with Decompensated Liver Disease: A Randomized Controlled Trial. J Interferon Cytokine Res. 2017 Nov;37(11):480-487.

D. Diabetes

D1. Sulksomboon N, Poolsup N, et al. Meta-analysis of the effect of herbal supplement on glycemic control in type 2 diabetes. J Ethnopharmacol. 2011;137(3):1328-1333.

D2. Derosa G, D’Angelo A, et al. The role of a fixed Berberis aristata/Silybum marianum combination in the treatment of type 1 diabetes mellitus. Clin Nutr. 2016;33(5):1091-1095.

D3. Voroneanu L, Nistor I, et al. Silymarin in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Diabetes Res. 2016;2016:5147468.

D4. Voroneanu L, Siriopol D, et al. Addition of silymarin to renin-angiotensin system blockers in normotensive patients with type 2 diabetes mellitus and proteinuria: a prospective randomized trial. Int Urol Nephrol. 2017 Dec;49(12):2195-2204.

D5. Ebrahimpour-Koujan S, Gargari BP, et al. Lower glycemic indices and lipid profile among type 2 diabetes mellitus patients who received novel dose of Silybum marianum (L.) Gaertn. (silymarin) extract supplement: A Triple-blinded randomized controlled clinical trial. Phytomedicine. 2018 May 15;44:39-44.

D6. Hadi A, Pourmasoumi M, et al. The effects of silymarin supplementation on metabolic status and oxidative stress in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of clinical trials. Complement Ther Med. 2018 Dec;41:311-319.

E. Dyslipidemia

E1. Derosa G, Bonaventura A, et al. Berberis aristata/Silybum marianum fixed combination on lipid profile and insulin secretion in dyslipidemic patients. Expert Opin Biol Ther. 2013;13(11):1495-1506.

E2. Derosa G, Bonaventura A, et al. Effects of Berberis aristata/Silybum marianum association on metabolic parameters and adipocytokines in overweight dyslipidemic patients. J Biol Regul Homeost Agents. 2013;27(3):717-728.

E3. Derosa G, Romano D, et al. Berberis aristata/Silybum marianum fixed combination (Berberol(®)) effects on lipid profile in dyslipidemic patients intolerant to statins at high dosages: a randomized, placebo-controlled, clinical trial. Phytomedicine. 2015 Feb 15;22(2):231-237.

F. Inflammatory Bowel Disease

F1. Langhorst J, Wulfert H, et al. Systematic review of complementary and alternative medicine treatments in inflammatory bowel diseases. J Crohns Colitis. 2015 Jan;9(1):86-106. doi: 10.1093/ecco-jcc/jju007. Epub 2014 Nov 28. Review. PubMed PMID: 25518050.

G. Nonalcoholic Steatohepatitis

G1. Wah Kheong C, Nik Mustapha NR, et al. A Randomized Trial of Silymarin for the Treatment of Nonalcoholic Steatohepatitis. Clin Gastroenterol Hepatol. 2017 Dec;15(12):1940-1949.e8.

H. Safety

H1. Jalloh MA, Gregory PJ, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15.

H2. Asher GN, Corbett AH, et al. Common Herbal Dietary Supplement-Drug Interactions. Am Fam Physician. 2017 Jul 15;96(2):101-107.

H3. Han Y, Guo D, et al. Effect of silymarin on the pharmacokinetics of losartan and its active metabolite E-3174 in healthy Chinese volunteers. Eur J Clin Pharmacol. 2009 Jun;65(6):585-591.

H4. Izzo AA. Interactions between herbs and conventional drugs: overview of the clinical data. Med Princ Pract. 2012;21(5):404-28. doi: 10.1159/000334488. Epub 2012 Jan 11. Review. PubMed PMID: 22236736.

I. Trichotillomania

I1. refI1Grant JE, Redden SA, et al. Milk Thistle Treatment for Children and Adults with Trichotillomania: A Double-Blind, Placebo-Controlled, Crossover Negative Study. J Clin Psychopharmacol. 2019 Mar/Apr;39(2):129-134.

J. Ulcerative Colitis

J1. Rastegarpanah M, Malekzadeh R, et al. A randomized, double blinded, placebo-controlled clinical trial of silymarin in ulcerative colitis. Chin J Integr Med. 2015 Dec;21(12):902-6.

Last reviewed March 2020 by EBSCO NAT Review Board Eric Hurwitz, DC

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