Hi! Welcome to HCM! The GGT level is too sensitive, frequently elevated when no liver disease is apparent. A GGTP test is useful with an elevated alkaline phosphatase level OR with elevated SGOT/SGPT elevation of GGT supports alcoholic liver disease. An isolated elevation of the GGT level does not need to be further evaluated. Listerine is safe and has no harmful effect.So nothing to worry! Take care!