Is it safe to transition from a nicotine vaporizer to nicotine gum im 21 and they say brain continues to develops until 25. i was interested in nicotine as a nootropic which is why this started . i smoke first at 18 then on off with a break for a yea?

The faster you quit the better. No good can come from use of nicotine. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs.

Nicotine is highly addictive, and should be stopped completely ASAP. There is NO therapeutic or health rationale for use of nicotine. Instead, there is potential harm, especially with smoking and vaping. Contact your local doctor and use techniques to completely withdraw.