It is immaterial whether you take it before meal or after meal or even don't take it.
It has got no action and no useful therapeutic effects nor does it have any preventive action at all against liver disorders. No double blind trials have proved any useful therapeutic or preventive effects.
Moreover no medicine is required for liver as it does not require any for it.
If liver cells got damaged as in acute viral hepatitis, they get regenerated without any medicine to the extent of 90% provided the trabecular framework is not broken. It means that even if 90% of all your liver cells get damaged they would regenerated and recover themselves without any medicine.
If you take any medicine or drugs when your liver is ill and it's cells are damaged, the administerd medicines would put additional overload on liver and may exaggerate liver damage.
During damaged liver cells, only you have to take plenty of carbohydrates with plenty of water and B-complex required for carbohydrate metabolism. No fats and no proteins and no drugs or chemicals (present in preserved foods) and no drugs except B-complex vitamins.