Everyone is different.
I have to start at 1/4 pill for the first day or I feel real funky. I usually start dosing Wednesday for a trip that takes me to the elevations above 8,000' on Friday. You have to play around to get the dosing right for you. It took me about 5 years to get it right...and it ain't perfect.
Diamox is not a panacea. I still have problems with sleep and appetite but not headaches. If I don't push the first day I'm usually ok. If over exert, I will have problems with sleep and appetite, especially when I'm over 11,000'.
Before I started using Diamox, I had my worse case of AMS after two days of acclimatization. Good luck.
