My doctor put me on 200 mg but I have always been afraid to try that and done only 100 to 120 mg. I may ask for 200 weekly micro dosing to avoid a high htc and low ferritin. Bad enough 100 mg brought my htc to 52.5definitely....i reduced from 200 to 150mg and noticed also a bit increase in sleepiness. i think the key is to find a proper dose which works for you. at 200mg i was a bit to revved up to the point of some insomnia