My husband quit in February 2014 and I followed him a month latter. We started out with level 18 nicotine and now, almost a year latter, neither one of us has smoked a cigarette, and he is nicotine free and I am still on level 6. We get our store to mix our solution with no PG, because it irritated our throats. I'm in my late 50's and he is in his mid 60's, and we had both smoked all our lives. So happy the e-cig was invented!!!