What's a scientist to do?

Conflicting data makes a scientist crazy.

On one hand, some studies have suggested that uptake of nicotine from vaping might be as low as 10%.

On the other hand, I've produced data myself that shows an efficiency of around 40% in getting nicotine from the cart to the vapor.

In order to square my results with the studies, then a 25% efficiency from vapor to body would be required (for every 1 mg vaped, 0.4 mg makes it to the vapor, and for every 0.4 mg in the vapor, 0.1 mg is absorbed by the body).

It's generally accepted that an analog, depending on the type, will deliver between 0.5 and 1 mg of nicotine to the body (and for sake of argument, we'll assume this is indeed the case). So I smoke an ultra-light, and I do it just like the smoking machine protocol says but I don't smoke it all the way down, and I deliver 0.3 mg of nicotine to my bloodstream. Over the course of the day, I smoke 29 more analogs in the same way. Exactly 9 mg of nicotine has been delivered to my bloodstream. I continue on in this manner for oh, say 20 years.. each day, another 9 mg of nicotine, tick-tock, time goes on.

Then one day, I discover e-cigarettes and I stop smoking analogs entirely and take up with vaping. How much to vape? How many mL's, what strength? Hey.. I'll try 24 mg/mL and I don't have to worry about all that tar, so I'll just work it like I was born with that e-cig in my mouth. I go through 4 mL of that 24 mg every day for a few days. Man, I'm buzzing and feeling good! Sure my dreams are getting totally bizarre at night, and I've got the shakes, but no tobacco guilt! Then one evening, what's that in the pit of my stomach? Man, I feel sick, I'm going to throw up. Off to the bathroom a few times. I vape some more, here's comes that feeling again.. off to the bathroom again. Hmm.. maybe 4 mL of 24 mg is a little extreme for me. I knock it down to 4 mL of 6 mg per day. No more constant buzzing, no more shakes, no more crazy dreams, and yay! no more puking... and get this.. no craving for more nicotine. The novelty wears off a bit, and I'm only vaping 2 mL per day of the 6 mg, and something is missing.. I want nicotine. OK, I'll bump it up to 12 mg. So here I am vaping 2 mL of 12 mg per day.

Bliss.

The above paragraph roughly describes my introduction to, and the development of my vaping habit.

I compare my experience with the studies that say that only 10% of the nicotine vaped makes it into my system. Let's assume the 10% studies are correct:

Analogs: 9 mg of nicotine/day.
Initial vaping: 24 mg/mL at 4 mL/day.
10% efficiency? 24 mg/mL * 4 mL * 0.1 = 9.6 mg of nicotine/day.

Wow! This should be perfect! So why in the hell am I wired, shaking, dreaming tremulous dreams, and puking?

Because, the studies are WRONG. They are either just plain wrong, or "whuups, we forgot to take some x-factor into account" wrong.

So now I'll assume that I'm correct rather than the studies, and 40% of the vaped nicotine makes it into my system:

Analogs: 9 mg of nicotine/day.
Initial vaping: 24 mg/mL at 4 mL/day.
40% efficiency? 24 mg/mL * 4 mL * 0.4 = 38.4 mg of nicotine/day.

Sweet hell! No wonder I'm puking. I'm going on like I'm smoking 6 and a half packs of my old analogs per day.

But, seeing as I don't view buzzing, shaking, tremulous dreams, and puking as desired side-effects of my habit, I adjusted my liquid down:

Analogs: 9 mg of nicotine/day.
current vaping: 12 mg/mL at 2 mL/day.
40% efficiency? 12 mg/mL * 2 mL * 0.4 = 9.6 mg of nicotine/day.

Bliss.

Due to the fact that vaping 4 mL/day of 24 mg makes me sick, with all the symptoms of nicotine overdose, the 10% efficiency study must be and is wrong. As I said before, maybe plain wrong, maybe "failed to account for some x-factor" wrong. But all the same, wrong.

I look at the forum member who vapes 3 mL of 36 mg/day and posted results of a blood test for nicotine, cotinine, and I forget the other metabolite. Excellent information, but what's missing? The comparative data. Without a blood test showing this forum member's levels while smoking a couple packs/day of full-flavor analogs, the data is simply inconclusive.

(Edit: January 2010, It seems Exogenesis has found that e-cigs deliver far more nicotine than 40%, based on his excellent research, we may be looking at 90%+... so perhaps e-cigs deliver it all and we absorb around half of what's delivered?)