RF, If you order a kit, it will come with some of the pre-filled cartridges. You can specify when you order, if you want "high, med., low, or zero nicotine." The cartridges can then be refilled with the "juice," which contains the nicotine. I ordered from the American manufacturer I mentioned previously. Also, the suppliers I mentioned are very good to answer your questions. If you want to taper down from the nicotine, as in quitting, you can do so by going thru the different levels, just as in the patch. I haven't found that to be necessary, though I have all different levels of the nicotine juice. Whether I'm using the high or the low, I can abstain as long as I want with the ecig, unlike I was ever able to do with tobacco. PM me if you have any questions.
Patty