benadryl plus capsules work to relieve the symptoms of hay fever & other allergic conditions such as pet, skin or dust allergies plus associated congestion. these symptoms include blocked sinuses, stuffy nose, itchy & runny nose, itchy & watery eyes, sneezing & urticaria (hives & itchy skin rash)., active in 15 minutes, lasts 8 hours, contains pseudoephedrine to relieve congestion from hay fever or allegie