Yes, nicotine at low dose has a stimulant effect who explains most of that. But its tolerance builds up very quickly and most habitual smokers don't really feel

Yes, nicotine at low dose has a stimulant effect who explains most of that. But its tolerance builds up very quickly and most habitual smokers don't really feel this effect anymore and have to smoke more. At high dosage its effect turns from stimulant to sedative and reduce neuronal activity. On the anecdata side, I have a few smoker friends who explained to me they only really feel the first cigarette in the morning. All the others cigarettes they smoke are due to habit/withdrawal. In the end, there are a lot of stimulant drugs who do not have as much side effects as nicotine, especially when it comes in the form of tobacco, so it does not appear like smoking is a possible rational choice.