As far as i have read gums and chantix (champix) and other nicotine replacement medicines do use a bunch of other chemicals to actually take the nicotine to ur blood/brain (champix being the most "effective" but still having like 160 or so dangerous chems), problem with this and is why i went cold turkey from start is:
1- You can easily get addicted to gums and medicines containing nicotine (or replacement), taking around 6 months to quit the gums and read coutless cases where people got addicted to it for over 10 years.
2- After quiting smoking using medicines and then quiting the medicine addiction the rate of people that managed to go past 1 year without returning to smoke is of 1 in 11 and from that fraction 75% return to cigarettes before 3 years pass.
It seems the e-cig contains only the nicotine and whatever the
juice flavor uses, so is far less harmful than a nicotine gum and it provides the illusion that you are still smoking that must help a whole lot by itself.