Milk Thistle
Silybum marianum, Chardon-Marie
Efficacy
- Indications with possible efficacy:
None - Indications with possible, but poorly documented efficacy :
Amanita poisoning (mushroom) - intravenously
Dyspepsia (popular use) - Other indications but with no proof of efficacy:
Diabetes
Liver disease
Lactation stimulation
Security
- Risk of Drug Interactions: Low
- Adverse Effects: Rare
Description
Part of the plant used: seeds
Milk thistle grows extensively in every part of the world. Because it can grow easily in many habitats, it is often found along the edge of our roads. This tall plant, 5 to 10 feet high, has thorny leaves and purple flowerheads. The seeds obtained from dried flowerheads are used for their medicinal properties. Milk thistle has been used by man for over two thousand years. It apparently has antioxidant properties as well as a protective effect on the liver. These effects are attributed to silyramine, a mix of three isomers (silibilin, silichristin and silidianin) found in the seeds. Silyramine is weakly soluble in water, which explains why water-based products, such as tea, are ineffective. Oral use requires a concentrated product. The mechanisms of action of milk thistle are still not clearly established. Milk thistle appears to improve liver regeneration, stop liver toxins from penetrating into liver cells and impair the oxydative action of free radicals.
Direction of use
- Amanita poisoning:
Usual dosage :
20 to 50 mg/kg/day administered intravenously within 48 hours of ingestion of Amanita phalloides (this product is not available in North America). - Dyspepsia:
Usual dosage :
3 to 15 grams of milk thistle seeds (maximum of 4 grams per dose) or 140 to 630 mg daily of a 70 to 80% silyramine extract is recommended (maximum of 210 mg per dose). - Liver diseases:
Usual dosage :
3 to 15 grams of milk thistle seeds (maximum of 4 grams per dose) or 140 to 630 mg daily of a 70 to 80% silyramine extract is recommended (maximum of 210 mg per dose).
There is insufficient reliable information to conclude that milk thistle is effective in any other indication.
Precautions
- Side effects
Milk thistle is not associated with any particular toxicity. Some individuals may experience mild and transient diarrhea, headache or skin reactions. - Contraindications
Some people allergic to plants from the Asteraceae/Compositae family (ragweed, chrysanthemums, daisies, etc.) may be allergic to milk thistle. - Pregnancy and breastfeeding
Even though some authors claim that milk thistle can be used safely by pregnant and breast-feeding women, no safety data are available concerning its use during pregnancy and breast-feeding. Pregnant and lactating women should be prudent and avoid milk thistle products.
Warning
In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.
Medicinal plant contents vary naturally from plant to plant - just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.
For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.
References
- Blumethal M and al. The Complete German Commission E monographs, 1998
- Natural Medicines Comprehensive Database, Therapeutic Research Faculty, 2010
- Lininger S. and al. The Natural Pharmacy, Prima Health, 1998
- Facts and Comparisons, The review of Natural Products, 2000
- Lexi-comp, Natural Therapeutics Pocket Guide, 2000-2001
- Passeportsanté.net. Chardon-Marie. www.passeportsante.net
- Barnes J. and al. Herbal Medicines, 2nd edition, Pharmaceutical Press, 2002
- Herbal Companion to AHFS DI, American Society of Health-System Pharmacists, 2001
- Rotblatt M. and Ziment I. Evidence-Based Herbal Medicine, Hanley & Belfus, 2002
- The Review of Natural Products, 6th Edition, 2010
- Health Canada, Natural Products Database
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.