I LOVE Zyrtec. It's my go-to anti-allergen. I'm allergic to everything except food (that I know of). Year round I take this and Flonase. They work supremely well together. I feel normal when I properly take them, otherwise, I'm mucus-y, itchy, and uncomfortable.
It relieves all my symptoms and blocks the subsequent headaches that arise from being so uncomfortable. I would highly recommend it for anyone with allergies: pets, weeds, outside, dust, etc. It's amazing.