I smoked for 22years before switching to an e cigarette.I use a mod refillable tanks with variable voltage batteries. I stopped smoking entirely after purchasing my starter kit. With no transition time,i completely stopped smoking. I had tried nicotine patches, and chantix prescribed by my doctor with zero success.I started using a high nicotine level liquid at about 1.8% and have gradually reduced it to 1.4% since switching to an e cigarette in jan.of 2013. I have noticed since switched that I no longer have shortness of breath, night sweats,and no more coughing and flegm in the mornings when I wake up.its been so much easier to stop smoking with an e cigarette and gradually reduce the nicotine because it fills the physical hand to mouth habit without all the toxins associated with tobacco use.I love it and its been a life saver, quite literally.