I'm on week 4 of quitting smoking. The e-cigarette has helped a lot. I have to confess that this week was the hardest. Not for cravings, that the e-cigarette has really solved. My problem, that I hoped to avoid was what I call "brain fog." Last time I quit (for 1 1/2 years) that brain fog, lethargy and concentration difficulty was what finally made me give in. It just wouldn't go away! I had hoped that the e-cigarette would help me avoid the brain fog, but no luck on that. I guess it isn't the nicotine withdrawal that causes that. Perhaps the withdrawal of all the other toxins, but if it lasts the way it did last time, I don't know what I'll end up doing.