Dr (Cyriac) Abby Philips is a crusader on Twitter against quackery. On Twitter he always responds to queries.

Here are excerpts from his responses:
1. Is Milk Thistle good for the liver?

Response: 
Sylimarin or milk thistle has not been found to be effective in any liver disease, however proper trials are still lacking to prove its benefits. Currently no recommendations for its use.

Here is the Cochrane link:

No evidence supporting or refuting milk thistle for alcoholic and/or hepatitis B or C virus liver diseases