I'm not exactly an allergy pro - mine are pretty mild, well at least the bad symptoms only last for a week or two.... so it took me a long time to figure out it was an allergy and not just a cold in the spring time. (its cedar pollen that tips me over the edge and I think moving to the PNW made symptoms worse and more noticable!) I'd still from my experience give a big thumbs up to Allegra - all it does is make me feel normal again. I think its works a bit differently from a lot of antihistimes, so dry mouth/nose/jitters/drowsiness aren't even listed as side effects, only dizziness which I can't recall ever having experienced.