I was prescribed 1 mg once daily but split my dose up to .5 mg twice daily. That seemed to work best for me as it helped get me through the day and allowed me to get a good nights sleep.

There have been days when I'd take up to 2 mg a day but 1 mg usually got me through. 20 mg sounds like a very high dose to me. 2 mg mellows me out, 20 mg would knock me out.