Why doesn't the box say "may cause drowsiness" on the MucinexDM?

OH by the way mucinex D and DM are different. im pretty sure DM is for night time but i would have to look at the ingredients to know

I appreciate your comment and the tip. (what does the D and DM stand for?) I investigated the drugs contained in the DM and found that it is in a lot of other cold medicines but usually in smaller amounts. I am seldom sick. I do not know a lot about drugs. I heard about Mucinex and decided to try it. The only kind they had was the "DM" on the shelf so I wasn't, at the time, aware of other kinds. How am I suppose to know which drug ingredient does what or is more likely to cause drowsiness. I read the box and it said nothing to that affect. I, like a lot of people, rely on the warnings on the box. I take responsibility for what goes into my body. My lesson learned it to ask a pharmicist before purchasing an unfamiliar product. I just thought I would let the makers of Mucinex know how it effected me in case they might want to ADD that as a WARNING on the label.