What is the strongest/most effective brand of antihistamines for seasonal allergies? It's mainly for a stuffy/runny nose.

The most effective antihistamine for seasonal allergies, especially for a stuffy or runny nose, is Aérius 5 mg. It does not cause drowsiness and is typically taken once a day, making it very convenient during allergy season. It is effective against eye symptoms, nose itching, and sneezing, but may not completely relieve nasal congestion. After several days of regular use, nasal congestion may improve on its own. If it does not, a nasal cortisone spray may be prescribed for overall symptom relief, including nasal congestion.