Be cautious with herbs that are claimed to heal or cure. Always find out as much as possible before buying it.
Many herbs that are claimed to be beneficial in different illnesses can also be toxic. Some of them may even do more harm than good. A good rule of thumb is not to take anything you are not sure you need, and to avoid herbs that has not been clinically tested.
Silymarin (Milk Thistle) is one of the herbs that is safe, and that has been clinically tested to be really effective in protecting the liver.
The well known Liv.52 (Liver Care) has not been shown to have any effect on patients with alcoholic liver cirrhosis. Instead increased liver-related mortality was found in one group.
Here is a link to a site about herbal medications to avoid: