[joshcanhelp]

If you buy from legitimate sources, you do. There are quality liquid producers that only use FDA-regulated flavors and sweeteners, organically-source vegetable glycerin, nicotine, and water. You can buy cheap from producers overseas, and I'm sure many do, but you can be as picky with your liquid as you can with what you eat.

[nerfhammer]

lacking regulation you have no idea if such claims in their marketing material are even true

[Game_Ender]

Even with regulation you still have to trust the companies making products. Most regulations do not require statistically significant independent sampling of every batch of product people consume. With such independent testing, you are going to have to trust the producer.

[nerfhammer]

That would make sense if the penalty of finding a tainted batch were to send it back for another one. However, the case is that if you ever get caught selling tainted products you could get shut down completely.