Milk Thistle
Research reviewed: up until 03/2025
Milk Thistle (Silybum marianum) is a dietary supplement with 25 published peer-reviewed studies involving 1,925 participants, researched for Liver Health, Hepatitis, Diabetes / Blood Sugar and 9 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Liver Health
StrongHepatitis
WeakDiabetes / Blood Sugar
StrongKidney Health
StrongCancer / Chemotherapy Support
StrongIron Overload
StrongMental Health
ModerateJoint Health
ModerateWomen's Health
StrongProstate Health
ModerateBrain Health
ModerateSkin Health
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Liver Health
To determine the effect of silymarin on patients with cirrhosis of the liver.
Study Type
Randomised controlled trial
Purpose
To determine the effect of silymarin on patients with cirrhosis of the liver.
Dose
420 mg/day of silymarin (3 x 140 mg capsules) or placebo
Participants
170 patients with cirrhosis of the liver
Duration
2 years
Results
The researchers observed a higher survival rate in the silymarin treatment group (82%) compared to placebo (68%). An association was found between silymarin treatment and a 58% survival rate 4 years after the trial, compared to only 38% in the placebo group. Survival differences were most evident in patients with alcohol-related liver disease and those with low-severity cirrhosis.
To investigate the effects of silymarin on the chemical, functional, and morphological features of liver disease.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To investigate the effects of silymarin on the chemical, functional, and morphological features of liver disease.
Dose
420 mg/day silymarin or placebo
Participants
97 in-patients with liver disease
Duration
4 weeks
Results
The study found an association between silymarin and significant decreases in serum ALT and AST levels (elevated liver enzymes indicating liver damage). Sulfobromophthalein retention also returned to normal significantly more often in the silymarin group. Microscopic examination of liver tissue revealed notable improvements in more participants from the silymarin group (11 out of 15) compared to placebo (4 out of 14). No side effects were recorded.
To evaluate silymarin for the treatment of biopsy-proven nonalcoholic steatohepatitis (NASH).
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate silymarin for the treatment of biopsy-proven nonalcoholic steatohepatitis (NASH).
Dose
2100 mg/day silymarin (700 mg three times daily) or placebo
Participants
99 patients with biopsy-proven NASH
Duration
48 weeks
Results
Silymarin treatment was associated with a significant reduction in liver fibrosis scores compared to placebo. The treatment group showed improvement in histological features of NASH, suggesting silymarin may help reduce liver scarring in non-alcoholic fatty liver disease.
To evaluate the safety and efficacy of oral silymarin for non-cirrhotic nonalcoholic steatohepatitis (NASH).
Study Type
Multicenter, Phase II, double-blind, placebo-controlled trial
Purpose
To evaluate the safety and efficacy of oral silymarin for non-cirrhotic nonalcoholic steatohepatitis (NASH).
Dose
Silymarin 420 mg or 700 mg three times daily vs placebo
Participants
99 adults with non-cirrhotic NASH
Duration
48 weeks
Results
The SyNCH trial found that silymarin was safe and well-tolerated at high doses. While the primary endpoint of a 30% decline in the NASH Activity Score was not met, there were trends toward improvement in steatosis and hepatic inflammation, and no serious drug-related adverse events were reported.
To evaluate the effect of silymarin supplementation on NAFLD grade in patients undergoing bariatric surgery.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate the effect of silymarin supplementation on NAFLD grade in patients undergoing bariatric surgery.
Dose
560 mg/day silymarin or placebo
Participants
52 patients with NAFLD undergoing bariatric surgery
Duration
8 weeks
Results
Silymarin supplementation was associated with a significant improvement in NAFLD grade compared to placebo. The treatment group showed greater reductions in liver fat accumulation and improvement in liver enzymes following bariatric surgery.
To evaluate the effects of silymarin on liver stiffness and gut microbiota in patients with metabolic dysfunction-associated steatotic liver disease (MASLD).
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate the effects of silymarin on liver stiffness and gut microbiota in patients with metabolic dysfunction-associated steatotic liver disease (MASLD).
Dose
Silymarin standardized extract or placebo
Participants
83 patients with MASLD
Duration
24 weeks
Results
Silymarin treatment was associated with significant improvement in liver stiffness as measured by transient elastography (FibroScan). The treatment group also showed favorable changes in gut microbiota composition, suggesting a potential gut-liver axis mechanism for silymarin's hepatoprotective effects.
Hepatitis
To determine the efficacy and safety of oral silymarin for chronic hepatitis C virus (HCV) infection in patients who had not responded to interferon-based therapy.
Study Type
Randomised, double-blind, placebo-controlled trial (SyNCH Trial)
Purpose
To determine the efficacy and safety of oral silymarin for chronic hepatitis C virus (HCV) infection in patients who had not responded to interferon-based therapy.
Dose
Silymarin 420 mg or 700 mg three times daily vs placebo
Participants
154 patients with chronic HCV who were nonresponders to prior antiviral therapy
Duration
24 weeks
Results
In this rigorous JAMA-published trial, silymarin at either dose did not significantly reduce serum ALT levels compared to placebo. The primary outcome of achieving ALT below 45 U/L was not met. While the supplement was well-tolerated, the results suggest silymarin may not be effective as monotherapy for chronic hepatitis C nonresponders.
To evaluate the efficacy of silymarin in the treatment of acute clinical hepatitis.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate the efficacy of silymarin in the treatment of acute clinical hepatitis.
Dose
420 mg/day silymarin or placebo
Participants
105 patients with acute hepatitis
Duration
4 weeks
Results
Silymarin treatment was associated with significantly faster resolution of symptoms including jaundice, dark urine, and abdominal discomfort compared to placebo. Liver enzyme levels (AST, ALT) normalized more rapidly in the silymarin group, suggesting potential benefit in acute hepatitis management.
Diabetes / Blood Sugar
To evaluate the effect of silymarin on glycemic control in patients with type 2 diabetes mellitus.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate the effect of silymarin on glycemic control in patients with type 2 diabetes mellitus.
Dose
600 mg/day silymarin (200 mg three times daily) or placebo, in addition to conventional therapy
Participants
51 patients with type 2 diabetes
Duration
4 months
Results
Silymarin treatment was associated with significant reductions in HbA1c (glycated hemoglobin), fasting blood glucose, total cholesterol, LDL cholesterol, and triglyceride levels compared to placebo. HDL cholesterol levels were significantly increased. These findings suggest silymarin may improve glycemic and lipid profiles in type 2 diabetes when used as an adjunct to standard therapy.
To investigate the effects of silymarin on glycemic indices and lipid profiles in type 2 diabetes patients.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To investigate the effects of silymarin on glycemic indices and lipid profiles in type 2 diabetes patients.
Dose
420 mg/day silymarin or placebo
Participants
40 patients with type 2 diabetes
Duration
45 days
Results
Silymarin supplementation was associated with significant reductions in fasting blood glucose and insulin levels compared to placebo. Improvements in insulin resistance markers (HOMA-IR) were also observed, along with favorable changes in lipid parameters, suggesting silymarin may improve insulin sensitivity in diabetic patients.
Kidney Health
To assess the effect of silymarin on urinary albumin excretion in patients with diabetic nephropathy.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To assess the effect of silymarin on urinary albumin excretion in patients with diabetic nephropathy.
Dose
420 mg/day silymarin (140 mg three times daily) or placebo
Participants
60 patients with type 2 diabetic nephropathy
Duration
3 months
Results
Silymarin treatment was associated with a significant reduction in urinary albumin-to-creatinine ratio (UACR), indicating reduced proteinuria. The treatment group also showed decreases in urinary TNF-alpha and MDA levels (markers of inflammation and oxidative stress), suggesting silymarin may have renoprotective effects through anti-inflammatory and antioxidant mechanisms.
To evaluate the nephroprotective effect of silymarin in cancer patients receiving cisplatin-based chemotherapy.
Study Type
Randomised controlled trial
Purpose
To evaluate the nephroprotective effect of silymarin in cancer patients receiving cisplatin-based chemotherapy.
Dose
420 mg/day silymarin or standard care
Participants
60 cancer patients receiving cisplatin
Duration
Duration of chemotherapy cycles
Results
Patients receiving silymarin alongside cisplatin showed significantly less decline in renal function markers (serum creatinine, BUN, creatinine clearance) compared to the control group. Silymarin appeared to provide nephroprotection against cisplatin-induced kidney toxicity without interfering with the antitumor activity of chemotherapy.
Cancer / Chemotherapy Support
To evaluate topical silymarin for prevention of hand-foot syndrome (HFS) in cancer patients receiving capecitabine chemotherapy.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate topical silymarin for prevention of hand-foot syndrome (HFS) in cancer patients receiving capecitabine chemotherapy.
Dose
Topical silymarin cream applied to hands and feet or placebo cream
Participants
40 cancer patients receiving capecitabine
Duration
9 weeks
Results
Topical silymarin application was associated with significant reduction in the severity and incidence of hand-foot syndrome compared to placebo. Patients in the silymarin group maintained better hand and foot function and reported less pain, suggesting silymarin cream may help manage this common chemotherapy side effect.
To evaluate silymarin for reducing gastrointestinal toxicity in colorectal cancer patients receiving FOLFIRI chemotherapy.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate silymarin for reducing gastrointestinal toxicity in colorectal cancer patients receiving FOLFIRI chemotherapy.
Dose
Silymarin 420 mg/day or placebo during chemotherapy cycles
Participants
70 colorectal cancer patients
Duration
Duration of FOLFIRI treatment
Results
Silymarin supplementation was associated with significantly less chemotherapy-induced diarrhea and nausea compared to placebo. The treatment group had fewer grade 3-4 gastrointestinal adverse events and required fewer dose reductions, suggesting silymarin may help maintain chemotherapy adherence by reducing GI toxicity.
To investigate the effect of silymarin on radiation-induced oral mucositis in head and neck cancer patients.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To investigate the effect of silymarin on radiation-induced oral mucositis in head and neck cancer patients.
Dose
Silymarin oral solution or placebo
Participants
27 head and neck cancer patients receiving radiotherapy
Duration
6 weeks
Results
Silymarin was associated with reduced severity of radiation-induced oral mucositis compared to placebo. The treatment group experienced delayed onset and lower maximum severity scores of mucositis, suggesting potential radioprotective benefits for the oral mucosa.
To evaluate topical silymarin for preventing radiodermatitis in breast cancer patients receiving radiation therapy.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate topical silymarin for preventing radiodermatitis in breast cancer patients receiving radiation therapy.
Dose
Topical silymarin cream or placebo cream applied to irradiated skin
Participants
40 breast cancer patients
Duration
5 weeks of radiotherapy
Results
Topical silymarin application was associated with delayed onset and reduced severity of radiation-induced dermatitis compared to placebo. The silymarin group showed less erythema, dry desquamation, and skin irritation in the irradiated area, suggesting silymarin cream may be a useful supportive measure during breast cancer radiotherapy.
Iron Overload
To evaluate silymarin as an adjunct to desferrioxamine for iron chelation in beta-thalassemia major patients.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate silymarin as an adjunct to desferrioxamine for iron chelation in beta-thalassemia major patients.
Dose
420 mg/day silymarin (140 mg three times daily) or placebo, alongside standard iron chelation therapy
Participants
97 patients with beta-thalassemia major
Duration
9 months
Results
The addition of silymarin to standard iron chelation therapy was associated with a significant decrease in serum ferritin levels compared to placebo plus chelation alone. The silymarin group showed greater iron unloading, suggesting silymarin may enhance the efficacy of iron chelation in transfusion-dependent thalassemia patients.
To evaluate the effect of silymarin on liver iron concentration in beta-thalassemia patients with iron overload.
Study Type
Randomised, double-blind, crossover trial
Purpose
To evaluate the effect of silymarin on liver iron concentration in beta-thalassemia patients with iron overload.
Dose
Silymarin 420 mg/day or placebo in crossover design
Participants
82 patients with beta-thalassemia and iron overload
Duration
12 weeks per crossover period
Results
Silymarin supplementation was associated with significant reductions in liver iron concentration as measured by MRI T2*. The crossover design confirmed the effect, with improvements observed during the silymarin phase and stabilization during the placebo phase, reinforcing silymarin's potential as an adjunctive iron-reducing agent.
Mental Health
To compare the efficacy of silymarin extract with fluoxetine in the treatment of obsessive-compulsive disorder (OCD).
Study Type
Randomised, double-blind, pilot trial
Purpose
To compare the efficacy of silymarin extract with fluoxetine in the treatment of obsessive-compulsive disorder (OCD).
Dose
600 mg/day silymarin (200 mg three times daily) vs 30 mg/day fluoxetine
Participants
35 adult outpatients with OCD
Duration
8 weeks
Results
Silymarin showed comparable efficacy to fluoxetine in reducing OCD symptoms as measured by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Both groups demonstrated significant reductions in symptom severity with no significant difference between treatments. Silymarin was well-tolerated, suggesting it may be a viable alternative for OCD treatment.
Joint Health
To evaluate the efficacy of silymarin as an adjunct therapy in patients with rheumatoid arthritis.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate the efficacy of silymarin as an adjunct therapy in patients with rheumatoid arthritis.
Dose
300 mg/day silymarin (150 mg twice daily) or placebo, in addition to standard disease-modifying antirheumatic drugs (DMARDs)
Participants
122 patients with rheumatoid arthritis
Duration
8 weeks
Results
Silymarin supplementation as adjunct to DMARDs was associated with significant reductions in Disease Activity Score (DAS28), tender and swollen joint counts, and inflammatory markers (ESR, CRP) compared to placebo plus DMARDs. The results suggest silymarin may provide additional anti-inflammatory benefit when combined with standard rheumatoid arthritis treatment.
Women's Health
To evaluate the effect of silymarin on pain symptoms and endometrioma volume in women with endometriosis.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate the effect of silymarin on pain symptoms and endometrioma volume in women with endometriosis.
Dose
280 mg/day silymarin (140 mg twice daily) or placebo
Participants
70 women with endometriosis
Duration
12 weeks
Results
Silymarin supplementation was associated with significant reductions in pelvic pain, dysmenorrhea, and dyspareunia compared to placebo. Endometrioma volume also decreased significantly in the treatment group. Inflammatory markers (IL-6, TNF-alpha) were reduced, suggesting silymarin's anti-inflammatory properties may benefit endometriosis management.
To evaluate the galactogogue effect of silymarin on breast milk production in mothers of preterm infants.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate the galactogogue effect of silymarin on breast milk production in mothers of preterm infants.
Dose
Silymarin standardized extract or placebo
Participants
100 mothers of preterm infants
Duration
25 days
Results
Mothers receiving silymarin produced significantly more breast milk compared to the placebo group. The daily milk volume increased progressively over the treatment period, suggesting silymarin may act as a galactogogue to support lactation in mothers of preterm infants who often struggle with milk supply.
Prostate Health
To evaluate the efficacy of silymarin in men with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH).
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate the efficacy of silymarin in men with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH).
Dose
Silymarin standardized extract or placebo
Participants
80 men with BPH-related LUTS
Duration
3 months
Results
Silymarin treatment was associated with significant improvement in International Prostate Symptom Score (IPSS) compared to placebo. Maximum urinary flow rate also improved, and prostate volume showed a trend toward reduction. The results suggest silymarin may help manage urinary symptoms associated with benign prostatic hyperplasia.
Brain Health
To evaluate the effect of silymarin on cognitive function in patients with mild-to-moderate Alzheimer's disease.
Study Type
Randomised, double-blind, placebo-controlled trial
Purpose
To evaluate the effect of silymarin on cognitive function in patients with mild-to-moderate Alzheimer's disease.
Dose
420 mg/day silymarin (140 mg three times daily) or placebo
Participants
36 patients with mild-to-moderate Alzheimer's disease
Duration
6 months
Results
Silymarin supplementation was associated with significant improvement in Mini-Mental State Examination (MMSE) scores compared to placebo. The treatment group showed stabilization or improvement in cognitive function, while the placebo group continued to decline. Oxidative stress markers were also reduced, suggesting neuroprotective mechanisms.
Skin Health
To investigate the effects of oral silymarin on acne.
Study Type
Randomised, single-blind, prospective, placebo-controlled clinical trial
Purpose
To investigate the effects of oral silymarin on acne.
Dose
210 mg/day of silymarin (3 x 70 mg tablets) or placebo
Participants
56 patients aged 14-30 years with acne
Duration
8 weeks
Results
A statistically significant association was found between silymarin supplementation and a reduction in the number of acne lesions at week 6 and 8 of treatment (-53% reduction in lesion count), whereas there was a non-significant reduction in the number of lesions in the placebo group.
Frequently Asked Questions
Common questions about Milk Thistle research
There are currently 25 peer-reviewed studies on Milk Thistle (Silybum marianum), involving 1,925 total participants. Research covers Liver Health, Hepatitis, Diabetes and 9 more areas. The overall evidence strength is rated as Very Strong.
The evidence is currently rated as "Very Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (25 human studies), and reported outcomes.
Milk Thistle has been researched for: Liver Health, Hepatitis, Diabetes, Kidney Health, Cancer Support, Iron Overload, Mental Health, Joint Health, Women's Health, Prostate Health, Brain Health, Skin Health. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 25 out of 25 studies are human trials. Human trials carry more weight in our evidence scoring system.
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