This is the very best medicine for my allergies, when it starts to get so bad I start to get asthma. I take half a pill, too much if you take a whole one. I take it in the morning because it speeds me up like I had a couple of cups of coffee. It really helps me get through this pollen season and has been no problem as long as I take it in the morning. Then I take benadryl half tablet or a whole one at night.