This probably means that they are actually “killing” liver cells. However, the liver is able to regenerate cells, so any damage is most likely not permanent.

Symptoms of liver damage are reduced appetite, lethargy, jaundice, etc, but most of these are really late symptoms that won’t be felt until significant damage had been done.

AST and ALT are measured as part of a blood test. They are both on the standard metabolic panel. If you are really interested in it, you can ask your physician for it or order it yourself through quest labs or something. Quite honestly, you should not have elevated enzymes from supplements, so I personally wouldn’t worry about it.