It's nicotine.

Head spins are when you intake more than you should or are used to. That's nicotine's most notorious symptom after having it. Go smoke a 16mg cigarette or put a patch on, you'll spin and probably puke. Even your vape friends would probably get light headed or spin too.

But then also there's the matter of it retailing at just $250 a gallon which would last some people up to a decade, most at least half a decade. The other 3 ingredients, water, vegetable glycerine and/or propylene glycol are even cheaper still since it's in so much food. And that's all that's needed. 4 super common and dirt cheap ingredients.

If anyone's adding things, they're burning money. If anyone taking the high risk of substituting, they're doing so for just a couple cents. But I don't know of anything that could substitute nicotine that doesn't cost at least 10× the price. It would be one of the moronic business decisions of all time.

You should educate yourself on the topic before asserting wildly incompatible assumptions as truth, them go barreling down conspiracies of how your assumptions are the big problem.

The truth of bad regulation is that nicotine is so cheap, manufacturers could put more in than advertised to give more hit and get users hooked on their brand over others without realising. Trying friends different ones, I'm sure some do. Some have big hits that feel higher mg than they're meant to be. Is that "the problem" though? Only if true.