Milk Thistle
Silybum marianum
水飞蓟
Pinyin: Shuǐ Fēi Jì
Plant Family
Asteraceae
Part Used
Seed (milk thistle seeds)
Origin
Mediterranean; naturalized worldwide
Safety Level
Safe
Overview
Milk thistle is a thistle with distinctive white veins on its leaves and purple flower heads. It has been used for over 2,000 years for liver and gallbladder conditions. The active compound silymarin is one of the most well-studied liver-protective substances. Milk thistle is the most commonly used herbal supplement for liver health worldwide.
Traditional Chinese Medicine Properties
Nature (四气)
cool
Flavors (五味)
bitter
Meridians (归经)
liver, gallbladder
Health Benefits
Traditional Uses
- Liver protection and detoxification
- Liver cirrhosis and hepatitis
- Gallbladder disorders and gallstones
- Mushroom poisoning (life-saving in some cases)
- Digestive disorders and indigestion
- Diabetes (blood sugar regulation)
- High cholesterol
- Skin conditions from liver imbalance (acne, eczema)
Active Constituents
The key compounds responsible for this herb's therapeutic effects:
Usage & Dosage
How to Use
Used as standardized extract capsules, tablets, tincture, and tea (tea is less effective because silymarin is not very water-soluble). The most effective supplements use standardized silymarin extract or enhanced absorption formulas.
Suggested Dosage
Standardized extract (70-80% silymarin): 140-420mg daily, divided into 2-3 doses. For liver protection: 140mg twice daily. For active liver disease: higher doses under supervision. Enhanced absorption formulas (Siliphos, etc.) can be taken at lower doses.
Quality & Storage
Harvest Season
Summer, when flower heads mature and seeds ripen. Seeds are threshed from dried flower heads.
Quality Indicators
Standardized extract should contain 70-80% silymarin. Look for silybin-phosphatidylcholine complex (Siliphos / Phytosome) for better absorption. Milk thistle seeds: shiny, black with white tuft. European-grown is generally high quality.
Storage
Seeds: airtight container, cool dark place, 2-3 years. Extract/capsules: follow manufacturer directions, typically 2-3 years.
Safety Information
Contraindications
Asteraceae/ragweed allergy (cross-reactivity possible)Pregnancy and breastfeeding (limited safety data)Hormone-sensitive cancers (breast, ovarian, uterine, prostate - silymarin has weak estrogenic effects in test tube studies)Children (insufficient safety data)Bile duct obstruction (consult doctor first - may increase bile flow)
Possible Side Effects
- Generally very safe and well-tolerated
- Mild digestive upset (laxative effect in high doses)
- Nausea and diarrhea
- Bloating and gas
- Headache (rare)
- Skin rash (rare - allergic reaction)
- One of the safest herbal supplements
Drug Interactions
- Liver-metabolized medications (CY450 - possible interactions, but less significant than many other herbs)
- Anticoagulants (warfarin - may increase effect, monitor INR)
- Diabetes medications (may lower blood sugar)
- Statin medications (may have additive cholesterol-lowering effect)
- Bromocriptine and other dopamine-related drugs
- Generally moderate interaction potential
- Important: If you have liver disease, consult your doctor before taking any supplements.
Note: Always consult with a qualified healthcare practitioner before starting any herbal supplement, especially if you are pregnant, nursing, have medical conditions, or take medications.
References & Research
Information on this page is based on traditional herbal knowledge and modern scientific research. For a comprehensive list of references, please refer to our full citations page.
ℹ️ Disclaimer
This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. The FDA has not evaluated these statements. Always consult a qualified healthcare provider before using herbal supplements.
Related Herbs
Dandelion Root
Taraxacum officinale
Dandelion is a common weed found almost everywhere, but it is also a valuable medicinal plant. Every part of the plant is usable: root, leaves, and flowers. Dandelion root is primarily used for liver and digestive health, while the leaves are more diuretic. It has been used in both European and Chinese herbal traditions.
Burdock Root
Arctium lappa
Burdock is a biennial plant with large leaves and prickly burrs that stick to clothing (the inspiration for Velcro). The long, brown root is used as both food (gobo in Japanese cuisine) and medicine. In traditional herbalism, burdock is considered a "alterative" or "blood purifier" - meaning it gradually restores proper function to the body, especially the skin, liver, and lymphatic system.
Dandelion Root
Taraxacum officinale
Dandelion is one of the most common yet underappreciated medicinal plants. Every part of the dandelion is edible and medicinal, from root to flower. The root is particularly valued as a liver tonic and digestive bitter, while the leaves are used as a diuretic and nutrient source. Dandelion has been used in both Western and Chinese herbal traditions.