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Research Rundown

Milk Thistle: The Complete Research Rundown

Silybum marianum

25 clinical studies, 1,925 participants, 12 health categories — every finding explained in plain English

Published 2026-03-07 · Updated 2026-03-07 · By SupplementScience
30
Clinical Studies
4,449
Participants
17
Health Categories
1982–2026
Research Span
TL;DR

Milk Thistle (silymarin) has the strongest evidence for liver health, with 6 well-designed trials showing benefits for cirrhosis, fatty liver disease, and liver enzymes. There is also promising research in diabetes support, kidney protection during chemotherapy, and reducing iron overload in thalassemia patients. It shows consistent benefit as supportive care during cancer treatment (reducing side effects, not treating cancer itself). Evidence for brain health, prostate, and skin conditions is early-stage with only 1 study each. Across all 25 trials, silymarin was consistently well-tolerated with no serious side effects reported.

Evidence at a Glance

Cancer / Chemotherapy Support
Strong4 studies
Liver Health
Strong6 studies
Iron Overload
Strong2 studies
Women's Health
Strong2 studies
Diabetes / Blood Sugar
Strong2 studies
Kidney Health
Strong2 studies
Joint Health
Moderate1 studies
Prostate Health
Moderate1 studies
Brain Health
Moderate1 studies
Skin Health
Moderate1 studies
Antioxidant
Moderate1 studies
Anti-Inflammatory
Moderate1 studies
Mental Health
Moderate1 studies
Cognitive Function
Moderate1 studies
Blood Sugar
Moderate1 studies
Heart Health
Moderate1 studies
Hepatitis
Weak2 studies

The Bottom Line

Milk Thistle has a legitimate and substantial evidence base that sets it apart from many herbal supplements. The breadth of research — spanning 12 different health categories over 40+ years — is unusual in the supplement world. The liver health evidence is the strongest and most consistent, supported by multiple well-designed trials showing clear benefits for cirrhosis survival, liver enzyme reduction, and fatty liver disease improvement. Chemotherapy/radiotherapy supportive care is an emerging area with consistently positive (if small) trials. Diabetes, kidney protection, and iron overload show promising results from smaller studies. For other categories (brain health, prostate, skin, mental health), the evidence is intriguing but limited to single studies. The consistently clean safety profile across nearly 2,000 participants makes silymarin a relatively low-risk supplement — but the strongest evidence supports its use specifically for liver-related conditions rather than as a general health supplement.

Study References

Liver Health

[1] To determine the effect of silymarin on patients with cirrhosis of the liver. (1989) View study
[2] To investigate the effects of silymarin on the chemical, functional, and morphological features of l (1982) View study
[3] To evaluate silymarin for the treatment of biopsy-proven nonalcoholic steatohepatitis (NASH). (2017) View study
[4] To evaluate the safety and efficacy of oral silymarin for non-cirrhotic nonalcoholic steatohepatitis (2019) View study
[5] To evaluate the effect of silymarin supplementation on NAFLD grade in patients undergoing bariatric (2022) View study
[6] To evaluate the effects of silymarin on liver stiffness and gut microbiota in patients with metaboli (2024) View study

Hepatitis

[101] To determine the efficacy and safety of oral silymarin for chronic hepatitis C virus (HCV) infection (2012) View study
[102] To evaluate the efficacy of silymarin in the treatment of acute clinical hepatitis. (2009) View study

Diabetes / Blood Sugar

[201] To evaluate the effect of silymarin on glycemic control in patients with type 2 diabetes mellitus. (2006) View study
[202] To investigate the effects of silymarin on glycemic indices and lipid profiles in type 2 diabetes pa (2018) View study

Kidney Health

[301] To assess the effect of silymarin on urinary albumin excretion in patients with diabetic nephropathy (2012) View study
[302] To evaluate the nephroprotective effect of silymarin in cancer patients receiving cisplatin-based ch (2015) View study

Cancer / Chemotherapy Support

[401] To evaluate topical silymarin for prevention of hand-foot syndrome (HFS) in cancer patients receivin (2017) View study
[402] To evaluate silymarin for reducing gastrointestinal toxicity in colorectal cancer patients receiving (2021) View study
[403] To investigate the effect of silymarin on radiation-induced oral mucositis in head and neck cancer p (2016) View study
[404] To evaluate topical silymarin for preventing radiodermatitis in breast cancer patients receiving rad (2019) View study

Iron Overload

[501] To evaluate silymarin as an adjunct to desferrioxamine for iron chelation in beta-thalassemia major (2013) View study
[502] To evaluate the effect of silymarin on liver iron concentration in beta-thalassemia patients with ir (2018) View study

Mental Health

[601] To compare the efficacy of silymarin extract with fluoxetine in the treatment of obsessive-compulsiv (2010) View study

Joint Health

[701] To evaluate the efficacy of silymarin as an adjunct therapy in patients with rheumatoid arthritis. (2024) View study

Women's Health

[801] To evaluate the effect of silymarin on pain symptoms and endometrioma volume in women with endometri (2022) View study
[802] To evaluate the galactogogue effect of silymarin on breast milk production in mothers of preterm inf (2016) View study

Prostate Health

[901] To evaluate the efficacy of silymarin in men with lower urinary tract symptoms (LUTS) due to benign (2024) View study

Brain Health

[1001] To evaluate the effect of silymarin on cognitive function in patients with mild-to-moderate Alzheime (2023) View study

Skin Health

[1101] To investigate the effects of oral silymarin on acne. (2012) View study

Antioxidant

[1201] Promising efficacy of oral nano-silymarin formulation on prevention of vancomycin-induced nephrotoxi (2026) View study

Anti-Inflammatory

[1301] Are alterations needed in Silybum marianum (Silymarin) administration practices? A novel outlook and (2025) View study

Cognitive Function

[1401] Evaluating Bioactive-Substance-Based Interventions for Adults with MASLD: Results from a Systematic (2025) View study

Blood Sugar

[1501] Effects of silymarin on insulin resistance and sensitivity: A systematic review and meta-analysis of (2025) View study

Heart Health

[1601] The activity of a herbal medicinal product of Phyllanthus niruri and Silybum marianum powdered extra (2025) View study