.....without thinking really as he seems miserable and full of cold. Then read the bottle and it is from 2 months. I am guessing it will do him no harm as he is a good size (11 lbs)... he did fall asleep within 20 minutes when he has been sleeping most of day.
My older kids seemed to sleep all the time when they were poorly too though.
He probably had a bit less than 2.5ml say 2.0 ml. Looking for re-assurance really.........