Is smoking e-cigarettes (vaping) OK after an FUE procedure? If not, how long should one wait before vaping again?

There are no studies on vaping and hair growth.  In general smoking is considered bad for wound healing.

kingstealth,Vaping or e-cigarette use delivers nicotine a powerful vasoconstrictor. Vasoconstriction diminishes blood flow, so it is not good for the transplant to decrease the blood flow to it. Good circulation brings oxygen, healing cells,and nourishment to the recovering tissues.All the best,Bernardino A. Arocha, MD

Smoking delays healing after any type of surgery or invasive procedure. This is not unique to hair transplant surgery.Good Luck

There are no studies that show that vaping is harmful to hair transplant people unlike cigarettes which do impact blood supply. If there is nicotine in the Vape, then the side effects of nicotine may produce vascular changes in the scalp but no one knows