Get 24-hour relief from allergy symptoms caused by ragweed, tree pollen, dust mites, pet dander hay fever and other upper respiratory allergies with Zyrtec Allergy Relief Medicine Tablets. With 10 milligrams of the antihistamine cetirizine hydrochloride per tablet, this prescription-strength allergy relief medicine provides 24 hours of relief from common symptoms of allergies including runny nose, sneezing, itchy, watery eyes, and itching of the nose or throat. From the #1 allergist-recommended brand among OTC oral antihistamines, these all-day anti-allergy tablets effectively treat indoor allergies caused by dust, mold, and pet dander, as well as outdoor seasonal allergies from tree pollen, weeds, and grasses. Zyrtec anti-allergy tablets work fast* at hour one and provide 24 hour relief for your indoor and outdoor allergies and work twice as hard when you take it again the next day. It is suitable for those ages 6 and older.