Diphenhydramine- better known as Benadryl- is not as popular as more modern antihistamines, like Loratadine (Claratin) , as it causes drowsiness, and only lasts a few hours. But it has one big advantage: It acts much faster than Loratadine, taking effect in minutes, rather than hours, and it works with one dose, whereas Loratadine can take several doses before having a significant effect. I use Loratadine on a regular basis during allergy season, but I also keep Diphenhydramine on hand for quick relief of allergic reactions to pollen, insect stings, plant allergies and more. It's always a part of my outdoor first air kit, too. And as some have noted, it's a good non-prescription sleep aid for occasional use. The Amazon price is right- less than a penny and a half per pill.