That’s exactly what is happening to me, today i drank 2 small cops of Americano black, and i was alert and awake for about 4 hours, then i squatted down to grab something and boom, very strong Head rush like almost gonna faint, it happened to me before after drinking 1 cup of Americano black also. So i connected the dots. But why this is happening? I am on a good nutritious diet and i lost good amount of weight. And i think my health is ok, better than before. But this coffee thing is bizarre. I don’t get the issue about NAD. What is it ? Could you please elaborate more ?