Hey Art hope you’re doing well. To add to Art’s wonderful explanation vaping only lasts a short time and many of us who suffer with PN will vape throughout the day as needed. Your statement about needing to wait until a specific time for your next hit intrigued me too? I have found that over time my pain control has increased, my mmj use has too but I no longer get buzzed, which is fine with me. You need to experiment to find your sweet spot and it took me a year.