Pay attention to what that Dr says at the end. It’s basically a crapshoot. Science just doesn’t know right now. It’s going to depend on your body and your genetics as to whether NAD+ is going to help you in the long run.... Harm you..or do nothing to you.
Btw..that author is a lawyer not a Dr...but what he says still stands..I will be dead before they ever have a study that is conclusive on the issue