I was a PAD Marlboro Medium 100s smoker, and started vaping just thursday. Haven't had an analog since Friday, and seem to be doing good with a few flavors of 24mg strength so far. I seem to vape quite a bit throughout the day, and when I sit around and do it a bit too much, I have noticed a bit of a headache, which I am attributing to a bit too much nicotine. However, I believe that for now I am at the right level.