I am on 5mg down from 10 because being drowsy, but I take other meds with drowsiness as side effects too. I find that I must get at least 9 hours of sleep or I will doze off on the couch if I sit too long. I will skip it if I have to get up before 7am because I am basically comatose otherwise. But I go to bed late, 11 or so, I dont work. My husband says I take it, think the word sleep and I'm out. I would consider asking not to take it but on the nights I skip, I barely sleep and no sleep med works on me. I cant take it early and try to stay up, it works in less than 15 min on me. If that long. I couldnt imagine 20mg but it could be weight dependent too as I am only a 5 ft woman 132 lbs