It is not necessary (in my opinion) to go above 25mg per day.
Incidentally, you can buy ephedrine hydrochloride over the counter in the UK... it's called chest-eeze - a product that also contains other thermogenic goodies like theophylline and caffeine...
DONT ABUSE EPHEDRINE!!!!!!!!!!!!! Many do. This is not good. Be careful with the CNS stimulants. They can tak the mind and nervous system and have you climbing the walls.