The pens are rated for 200-300 puffs but it will be really down to how much you will use it and how long your draws are. For some it lasts a week others 2 weeks. Personally I take 2-3 draws (2-3 sec) at any one time when I want to get high but can always feel it after one draw. The high is much cleaner then smoking with tobacco. I would argue this will get you as high as smoking but without the toxic chemicals releasedby combustion.