Milk thistle: benefits, dosage, contraindications
Other name(s)
Silymarin, wild artichoke
Scientific name(s)
Carduus marianus, Silybum marianum
Family or group:
Plants
Active ingredients:
Silymarin
Betaine
Mucilages
Flavonoids
Sterols
Indications
Scoring methodology
EFSA approval.
Type 2 diabetes ✪✪✪✪✪
Clinical studies have shown that taking milk thistle extract containing silymarin at a dose of 140 mg three times a day for 45 days reduces fasting blood glucose by 11% and insulin by 14%, and improves insulin resistance. There were also improvements in high-density lipoprotein (HDL) cholesterol levels, but not in low-density lipoprotein (LDL) levels or total cholesterol, compared with placebo.
Posologie
Oral: fruit
140 - 420 mg
3 - months
Adults
mother tincture, standardized extract
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.
Biliary disorders ✪✪✪✪✪
Milk thistle is traditionally used to relieve digestive disorders related to insufficient bile production. Silymarin is poorly soluble in water. As a result, water-based preparations of the product, such as herbal teas, are ineffective. For oral use, the product must be concentrated. The Commission E and the World Health Organization recognize the use of milk thistle in cases of dyspepsia.
Posologie
Oral: fruit, aerial parts
125 - 630 mg
Adults
standardized extract
Liver disorders ✪✪✪✪✪
Silymarin protects the liver by different mechanisms. It stabilizes the plasma membrane of the hepatocyte. It inhibits the absorption of certain toxins by preventing their binding to the cell surface and by blocking the membrane transport system of these poisons. In addition, it traps many free radicals through the formation of more stable and less reactive compounds. It also helps maintain the levels of glutathione and superoxide dismutase in the liver. In vitro, it increases the synthesis of hepatocyte proteins by stimulating RNA polymerase 1, which is involved in the synthesis of ribosomal RNAs, thus contributing to increased liver regeneration capacity.
Posologie
Oral: fruit
4 - weeks
Alzheimer's disease ✪✪✪✪✪
Preliminary clinical research shows that taking a supplement containing a 150 mg silymarin (milk thistle) extract in combination with ferulic acid, gamma-oryzanol, and apigenin orally twice a day for 3 months to 2 years may stabilize the mental functioning of patients with Alzheimer's disease
Posologie
Oral: fruit
300 mg
3 - months
Adults
dry extract
Synergies
Acne ✪✪✪✪✪
A small clinical trial in patients with acne vulgaris shows that taking 140 mg of silymarin orally daily for 2 months is effective in reducing the severity of acne. However, the use of silymarin in combination with doxycycline does not appear to be more effective than doxycycline alone.
Posologie
Oral: fruit
140 mg
2 - months
Adults
standardized extract
Hypercholesterolemia ✪✪✪✪✪
A meta-analysis of three clinical trials shows that taking a specific product containing 105 mg of milk thistle extract and turmeric twice a day for 3 months, along with diet and exercise, reduces LDL cholesterol levels compared with diet and exercise alone in hypercholesterolemic patients. There was no effect on HDL cholesterol or triglyceride levels. It is unclear whether the effects of this product are due to the milk thistle extract, the turmeric extract, or the combination.
Posologie
Oral: fruit
210 mg
3 - months
Adults
dry extract
Synergies
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.
The Effects of a Fixed Combination of Berberis aristata and Silybum marianum on Dyslipidemia - A Meta-analysis and Systematic Review.
Hepatic steatosis ✪✪✪✪✪
Clinical research in patients with nonalcoholic steatohepatitis shows that taking a milk thistle extract containing 700 mg of silymarin three times daily for 48 weeks improves fibrosis compared with placebo.
Posologie
Oral: fruit
2100 mg
48 weeks
Adults
silymarin
Parkinson's disease ✪✪✪✪✪
Clinical research shows that taking an oral supplement containing a milk thistle extract providing 150 mg of silymarin in combination with ferulic acid, gamma-oryzanol, and apigenin twice daily for 3 to 24 months may stabilize the clinical symptoms of Parkinson's disease in affected patients.
Posologie
Oral: fruit
300 mg
24 months
Adults
silymarin
Synergies
Cirrhosis ✪✪✪✪✪
Preliminary clinical research suggests that daily oral intake of a milk thistle extract providing 420 mg of silymarin for 4 years may improve liver function and reduce mortality in people with cirrhosis.
Posologie
Oral: fruit
420 mg
4 years
Adults
silymarin
Hepatitis ✪✪✪✪✪
In people with hepatitis, regardless of the cause, taking a 140 mg milk thistle extract containing 70% to 80% silymarin orally three times a day for 4 weeks improves certain symptoms, such as jaundice and dark urine, but does not improve liver enzymes. A randomized double-blind study including 57 patients with acute hepatitis A or B, treated daily with 420 mg of silymarin for 3 weeks, showed in the treated group a normalization of biochemical parameters (bilirubin, transaminases), reduced lengths of hospital stay, faster development of immunity, and a reduction in complications associated with the infection. In the case of chronic hepatitis, treatment with 420 mg of silymarin per day for 3 to 12 months improves histological parameters, without affecting biological or functional markers. However, analysis of clinical research concludes that any clinical effect of milk thistle in people with viral hepatitis is limited, and most results show that milk thistle has no significant effect on mortality, complications of liver disease, or liver histology.
Posologie
Oral: fruit
420 mg
4 - weeks
Adults
sylimarine, dry extract
Milk Thistle for Alcoholic and/or Hepatitis B or C Virus Liver Diseases
A randomized controlled trial to assess the safety and efficacy of silymarin on symptoms, signs and biomarkers of acute hepatitis.
[Results of Two Double-Blind Studies on the Effect of Silymarine in Chronic Hepatitis (Author's Transl)]
[Silymarin for the Treatment of Acute Viral Hepatitis? Report of a Controlled Trial (Author's Transl)]
Silymarin Use and Liver Disease Progression in the Hepatitis C Antiviral Long-Term Treatment Against Cirrhosis Trial
Detoxification ✪✪✪✪✪
In humans, milk thistle does not have a significant effect on CYP3A418, although in vitro silybin inhibits the activity of phase I metabolic pathways (Cytochromes CYP3A4 and CYP2C919). Silymarin also increases glucuronidation (a phase II detoxification reaction). nnFurthermore, silymarin is the only known medication that effectively protects against the phalloid Amanita toxin, which targets the liver, in combination with N-acetylcysteine.nn
Posologie
Oral: fruit
silymarin
Synergies
A review of plants used in the treatment of liver disease: part 1.
Assessing the clinical significance of botanical supplementation on human cytochrome P450 3A activity: Comparison of a milk thistle and black cohosh product to rifampin and clarithromycin
Chemotherapy ✪✪✪✪✪
Silymarin appears to increase the effectiveness of certain anticancer treatments by potentiating their cytotoxicity while simultaneously, in some cases, reducing their toxicity to healthy tissues. In vitro studies on different cell types show a synergy of silymarin with various anticancer agents (temozolomide, etoposide, irinotecan in glioma, doxorubicin in breast cancer). Other research appears to indicate that silymarin can mitigate the side effects of cancer treatments: in women with breast cancer, the application of a product containing a silymarin extract reduces the incidence of radiation-induced dermatitis and delays its onset compared with the application of a cream containing panthenol. Other preliminary clinical studies conducted on cancer patients receiving radiotherapy for the first time show that taking a product containing a silymarin extract from the first day of radiotherapy and for the following 6 weeks reduces the severity and delays the onset of radiation-induced mucositis compared with placebo. As part of an integrative approach, in addition to oncological care, the use of milk thistle is recommended, notably by the "Clinical Practice Committee of the Society of Integrative Oncology".
Posologie
Oral: fruit
420 mg
6 weeks
silymarin
Topical Use of a Silymarin-Based Preparation to Prevent Radiodermatitis : Results of a Prospective Study in Breast Cancer Patients
Integrating dietary supplements into cancer care.
Digestive disorders ✪✪✪✪✪
The EMA recognizes the traditional use of milk thistle preparations for the relief of dyspepsia and digestive disorders of hepatic origin, after exclusion of serious diseases.
Posologie
Oral administration: fruit
300 - 600 mg
dry extract
Metabolic syndrome ✪✪✪✪✪
Related to its effects on metabolism: see hypoglycemic and hypolipidemic properties.
Posologie
Oral administration: fruit
silymarin
Properties
Cholagogue
Silymarin from milk thistle is a very beneficial substance in the treatment or prevention of gallstones. Thus, it promotes bile flow by increasing its solubility. Indeed, studies have shown that taking milk thistle has caused a reduction of cholesterol in bile. Whenever bile flow is increased, the chances of developing a gallstone are reduced.
Usages associés
Digestive effect
Milk thistle is traditionally used to relieve digestive disorders related to insufficient bile production. Indeed, in Europe this plant is part of several pharmaceutical preparations containing bitter substances intended for the treatment of various digestive disorders of hepatic and biliary origin.
Usages associés
Hepatoprotective
Silymarin protects the liver through several mechanisms. It stabilizes the hepatocyte plasma membrane. It inhibits the uptake of certain toxins by preventing their binding to the cell surface and by blocking the membrane transport system of these poisons. In addition, it can trap many free radicals by forming more stable and less reactive compounds. It also contributes to maintaining glutathione and superoxide dismutase levels in the liver. In vitro, it increases the synthesis of hepatocellular proteins by stimulating RNA polymerase I, which is involved in ribosomal RNA synthesis, thus helping to increase the liver's regenerative capacity.
Usages associés
Antioxidant
Silybin reduces lipid peroxidation in various types of cell cultures and in an animal model. It also prevents glutathione depletion and protects DNA from degradation.
Hypoglycemic
Silymarin appears to reduce insulin resistance and to have a protective effect on the pancreas in in vivo experiments. Silymarin or isosilybin A decrease insulin resistance, in part through agonist action on the PPAR receptor (a key regulator of glucose and lipid metabolism). In vivo, modulation of insulin resistance has been observed through increased expression of PTEN (phosphatase and tensin homolog), which regulates important cellular functions. Furthermore, the use of silymarin is of interest for diabetes complications, such as diabetic nephropathy, which is thought to be caused by oxidative stress and inflammation. The protective effect on the kidney has been demonstrated in vivo: reductions in biochemical parameters (blood glucose levels, glycated hemoglobin (Hb), urine volume, blood uric acid, albuminuria) and histological improvement after 2 months of treatment with 60 to 120 mg/kg of silymarin.
Usages associés
Lipid-lowering
In human research, silymarin has been shown to lower levels of total cholesterol (TC), triglycerides (TG), and LDL cholesterol. Indeed, milk thistle can inhibit cholesterol acyltransferase, leading to reduced cholesterol absorption and lipoprotein biosynthesis. Moreover, silymarin inhibits HMG-CoA reductase, an enzyme involved in cholesterol metabolism. Milk thistle also decreases the synthesis of very low-density lipoproteins (VLDL) and the amount of free VLDL that can be secreted into the intestine. Additionally, by decreasing certain factors such as the peroxisome proliferator-activated receptor gamma (PPAR gamma), a transcription factor involved in the regulation of glucose-lipid metabolism, milk thistle reduces lipid accumulation.
Usages associés
Anti-inflammatory
In vitro, in different cell lines, silymarin reduces the inflammatory mediators TNF-α, NO and IL-6. Similarly, it blocks the expression of NF-κB (nuclear factor-kappa B), a protein involved in the immune response and the cellular stress response. In Kupffer cells (the liver macrophages), silybin inhibits leukotriene production. In an animal model of hepatic ischemia/reperfusion, a milk thistle extract significantly and dose-dependently reduces serum concentrations of inflammatory cytokines and liver enzymes (AST, ALT). Finally, in pancreatic β cells, silymarin inhibits NO (nitric oxide) production by inducible nitric oxide synthase (iNOS), which is induced by inflammatory cytokines.
Usages associés
Neurological
Because of its ability to inhibit oxidative stress in the brain and to modulate pathways such as β-amyloid peptide aggregation, inflammatory mechanisms, the apoptotic cellular machinery, and estrogen receptor–mediated signaling, silymarin has potential as a neuroprotective agent. It also exhibits an antidepressant effect that is at least partly related to its action on nitric oxide production. Moreover, silybin acts on two mechanisms of Alzheimer's disease: inhibition of acetylcholinesterase and of β-amyloid peptide aggregation.
Usages associés
Anti-aging
Thanks to its anti-inflammatory and antioxidant potential, milk thistle proves effective in combating aging. It attenuates oxidative damage and mitochondrial dysfunction in aging mice. Silymarin increases average lifespan, improves locomotor capacity, responsiveness to stimuli, and stress tolerance in an animal model.
Safe dosage
Adults 18 years and older: 600 mg - 1800 mg (dry extract)
Interactions
Médicaments
Antidiabetic: moderate interaction
Clinical research has shown that milk thistle extract, alone or combined with turmeric extract, can lower blood glucose and hemoglobin A1c (HbA1c) in patients with type 2 diabetes, including those already taking antidiabetic medications. Theoretically, this reduction could increase the risk of hypoglycemia in patients treated with antidiabetic drugs. Dose adjustments of antidiabetic medications may be necessary.
Estrogens: weak interaction
Animal research suggests that a silymarin extract from milk thistle binds to the estrogen receptor beta. Thus, milk thistle could interfere with estrogens by a competitive mechanism.
P-glycoprotein substrate: moderate interaction
In vitro research has shown that milk thistle can inhibit P-glycoprotein activity, which could increase the absorption of its substrates and thus enhance the drug's effect. Please use milk thistle with caution if you are taking P-glycoprotein substrates.
Raloxifene: moderate interaction
Laboratory research suggests that the milk thistle constituents silibinin and silymarin inhibit the intestinal glucuronidation of raloxifene. Theoretically, this could reduce clearance and increase raloxifene levels.
Rapamycin: moderate interaction
Pharmacokinetic research shows that a silymarin extract from milk thistle decreases the apparent clearance of rapamycin (sirolimus) in renal transplant recipients with hepatic impairment.
Tamoxifen: moderate interaction
Animal studies suggest that silibinin may increase plasma concentrations of tamoxifen and alter its conversion to an active metabolite. It is unknown whether this interaction occurs in humans. Use milk thistle with caution if you are taking tamoxifen.
Cytochrome P450 substrate: weak interaction
Silibinin is an inhibitor of some cytochrome P450 enzymes. Please use milk thistle with caution if you are taking cytochrome P450 substrates.
Precautions
Hormone-sensitive conditions: avoid
Silymarin, a constituent of milk thistle, may bind to the estrogen receptor beta. Thus, it could have estrogenic effects. Women with hormone-sensitive conditions should avoid using milk thistle. This applies to women who have had breast, uterine, or ovarian cancer, endometriosis, or uterine fibroids.
Type 2 diabetes: use with caution
Constituents of milk thistle could lower blood glucose in patients with type 2 diabetes. Diabetic patients using milk thistle products should be cautious and closely monitor blood glucose. Dose adjustments of antidiabetic medications may be necessary.
Pregnant women: avoid
Avoid use due to insufficient reliable information available.
Breastfeeding women: avoid
Avoid use due to insufficient reliable information available. Although milk thistle is used for its galactagogue properties, the WHO does not recommend its consumption for breastfeeding women.
Biliary tract obstruction: avoid
Milk thistle promotes bile flow by increasing its solubility; it is not recommended in case of biliary tract obstruction.
