For many centuries extracts of milk thistle have been recognized as "liver tonics". Research into the biological activity of silymarin and its possible medical uses has been conducted in many countries since the 1970s, but the quality of the research has been uneven. Milk thistle has been reported to have protective effects on the liver and to greatly improve its function. It is typically used to treat liver cirrhosis, chronic hepatitis (liver inflammation), toxin-induced liver damage (including the prevention of severe liver damage from Amanita phalloides ('death cap' mushroom poisoning), and gallbladder disorders.
Reviews of the literature covering clinical studies of silymarin vary in their conclusions. A review using only studies with both double-blind and placebo protocols concluded that milk thistle and its derivatives "does not seem to significantly influence the course of patients with alcoholic and/or hepatitis B or C liver diseases". A different review of the literature, performed for the U. S. Department of Health and Human Services, found that, while there is strong evidence of legitimate medical benefits, the studies done to date are of such uneven design and quality that no firm conclusions about degrees of effectiveness for specific conditions or appropriate dosage can yet be made.
A review of studies of silymarin and liver disease which are available on the web shows an interesting pattern in that studies which tested low dosages of silymarin concluded that silymarin was ineffective while studies which used significantly larger doses concluded that silymarin was biologically active and had therapeutic effects.
Other uses
Beside benefits for liver disease, other unproven treatment claims include:
- Lowering cholesterol levels
- Reducing insulin resistance in people with type 2 diabetes who also have cirrhosis[22][23]
- Reducing the growth of cancer cells in breast, cervical, and prostate cancers.
- Used in many products claiming to reduce the effects of a hangover[25]
- Used by individuals withdrawing from opiates, especially during the Acute Withdrawal Stage.
- Reducing liver damaging effects of chemotherapeutic drugs