Benadryl is the most powerful allergy medicine I have ever taken in my life. I generally do not like taking medicine when I am feeling ill. I prefer to tough it out and build up my immune system in a stronger way, although it takes much longer. However, in those dire situations where I absolutely need medicine to help me out, I take Benadryl.
For allergies, I have to take it because it becomes absolutely unbearable. Within 30 minutes or so after taking it, the medicine starts to work. I don't usually sneeze or anything, but I get real bad eye irritation and runny nose. Benadryl relieves almost all of the allergic problems.
I have taken Benadryl in the day even though it may cause drowsiness. Regardless of this side effect, I have not noticed much difference. I do feel slightly more tired but that can be associated with being sick in the first place. Usually, I take Benadryl at night before I go to bed and that is when I have the best sleep!