Can citirizin be useful for curing dark circle under my eyes?

Never heard of it! Sounds like most other gimmicks. Not much out there cures dark circles! just keep hydrated and hopefully you have good genetics!
Allergic shiners. If the dark circles are from "allergic shiners", Cetirizine will help. If the dark circles are hereditary or from poor sleep, Cetirizine will not help.