Has anyone tried this? What exactly are the benefits and drawbacks? How do you mix it? Details please. Seems like a good way to push through the afternoon drudge.
The only real reason to put caffeine in ejuice (other than in insanely high doses compared to the recommended levels) is to use its flavoring aspect to make a bitter/sour flavor.
Consider - nicotine is far stronger than caffeine. You can drink a source of 100mg of caffeine really quickly. So unless you vape 1ml of juice at a time, and that juice was 100mg/ml of caffeine (or more) you really aren't accomplishing much.
And even then, the bioavailability of caffeine through the lungs is not anywhere near oral administration. That 1ml of 100mg/ml probably only got about 10mg of caffeine into your blood. That's nothing.
As a neutral-ish opinion on something always hit hard with negativity.
There hasn't been thourough and well-documented scientific studies into it.
It just seems from small research from some people round these parts that inhaling caffeine is incredibly inefficient and doesn't do anything.
While it's amateur research, it's common sense as well. You need about 100mg of caffeine for a strong dose. It's not feasible to vape that much in a reasonable amount of time, without having it taste so strong you puke.