That's a great question, sandybeach, and similar to the thoughts I was having while progressing through this thread. If the lightheadedness is a result of carbon monoxide, it would seem reasonable to expect that same result following every cigarette; not just the first one.
I don't have the answer, but my recent experience vaping juice with WTA (whole tobacco alkaloids) yields a similar lightheadedness after a couple of minutes. It isn't as immediate, or as strong as from the first analog of the day, but it's a noticeable sensation. I sincerely doubt it's caused by carbon monoxide in the vapor, and attribute the effect directly to WTA that I was getting while smoking (along with all the other chemicals resulting from burning tobacco - including carbon monoxide).
In comparison, I don't experience any type of lightheadedness with 'nic only' juice. What's more, I tend to think upping the nic level to the point lightheadedness occurs would probably be associated with an increase in blood pressure (not good).
I have noticed though, in order to literally
feel the effect of WTA in my first morning vape, I have to limit my use of WTA juice during the last half of the day; probably because it has to clear out of my system before morning. At any rate, I don't use WTA juice to
feel the effect, but to satisfy and quell my tendency to chain vape, and it's doing THAT very well.
