Milk Thistle
Also known as: Silymarin, Silybum marianum, Silibinin
The most well-researched hepatoprotective herb — evidence-backed for liver protection, detoxification support, and antioxidant defense.
What it is
Milk thistle (Silybum marianum) is a flowering herb whose seeds contain a complex of flavonolignans collectively called silymarin. Silybin (or silibinin) is the most biologically active component. Milk thistle has been used medicinally for liver conditions for over 2,000 years and remains among the most-studied herbal supplements for hepatic applications — with evidence ranging from alcoholic liver disease to NAFLD and drug-induced liver injury.
How it works
Silymarin exerts hepatoprotective effects through multiple mechanisms: competitive inhibition of toxin binding to hepatocyte membrane receptors, stimulation of RNA polymerase I to enhance protein synthesis and liver cell regeneration, antioxidant activity protecting against lipid peroxidation and free radical damage, and anti-inflammatory activity through NF-κB inhibition. It also has modest anti-fibrotic properties, reducing collagen synthesis in activated stellate cells.
Clinical dose range
420–600 mg silymarin/day (divided into 3 doses)
Dose refers to silymarin content (the standardized extract), not total herb weight. Most studies use 420–600 mg/day of silymarin in three divided doses (140–200 mg three times daily). Silybin-phosphatidylcholine complex (Siliphos) has enhanced bioavailability and may be effective at lower doses.
Forms comparison
What to look for on the label
- Standardized to ≥70% silymarin on label
- Dose 420–600 mg silymarin/day achievable from the serving size
- Third-party tested for heavy metals and pesticides
- Phospholipid complex form if available for superior absorption
Health goals supported
Safety & dosing notes
Excellent safety record in clinical trials. Mild laxative effect at high doses. May slightly lower blood sugar — caution in diabetics on medication. A member of the daisy family — possible cross-reactivity in those with ragweed allergy.
SuppsBuddy validates silymarin standardization percentage and total dose per serving. Products using non-standardized milk thistle powder receive a low ingredient form score regardless of dose claimed.
Frequently asked questions
What is Milk Thistle?
Milk thistle (Silybum marianum) is a flowering herb whose seeds contain a complex of flavonolignans collectively called silymarin. Silybin (or silibinin) is the most biologically active component. Milk thistle has been used medicinally for liver conditions for over 2,000 years and remains among the most-studied herbal supplements for hepatic applications — with evidence ranging from alcoholic liver disease to NAFLD and drug-induced liver injury.
How does Milk Thistle work?
Silymarin exerts hepatoprotective effects through multiple mechanisms: competitive inhibition of toxin binding to hepatocyte membrane receptors, stimulation of RNA polymerase I to enhance protein synthesis and liver cell regeneration, antioxidant activity protecting against lipid peroxidation and free radical damage, and anti-inflammatory activity through NF-κB inhibition. It also has modest anti-fibrotic properties, reducing collagen synthesis in activated stellate cells.
What is the typical clinical dose range for Milk Thistle?
420–600 mg silymarin/day (divided into 3 doses). Dose refers to silymarin content (the standardized extract), not total herb weight. Most studies use 420–600 mg/day of silymarin in three divided doses (140–200 mg three times daily). Silybin-phosphatidylcholine complex (Siliphos) has enhanced bioavailability and may be effective at lower doses.
What forms of Milk Thistle should I look for?
Standardized extract (70–80% silymarin): Most studied; consistent silymarin content | Siliphos® (silybin-phosphatidylcholine complex): ~10× better bioavailability than standard extract | Non-standardized milk thistle powder: Silymarin content variable; clinical effect unpredictable
Is Milk Thistle safe?
Excellent safety record in clinical trials. Mild laxative effect at high doses. May slightly lower blood sugar — caution in diabetics on medication. A member of the daisy family — possible cross-reactivity in those with ragweed allergy. This information is educational and is not medical advice.
How does SuppsBuddy evaluate Milk Thistle?
SuppsBuddy validates silymarin standardization percentage and total dose per serving. Products using non-standardized milk thistle powder receive a low ingredient form score regardless of dose claimed.
Related ingredients
This page is for educational purposes only. These statements have not been evaluated by the FDA. This information is not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before starting any supplement.