Silymarin keeps certain organic poisons from entering the cells of the liver. For this reason, milk thistle is the preferred antidote for deathcap mushroom poisoning.
Milk thistle works directly against cancer cells in the cervix and prostate. Studies suggest it can both slow and stop their growth. Ovarian and breast cancer patients on chemotherapy are given milk thistle extract to increase the treatment's effectiveness.
In the liver, milk thistle extract promotes the growth of new liver cells and protects existing cells from the negative impact of free radicals. This is due to the action of the four antioxidants in silymarin. This makes milk thistle effective against the action of hepatitis, cirrhosis and acetaminophen (Tylenol) poisoning.