BDub

Good day! Total newbie here. If this has been posted before, I apologize. I searched high and low, and did not see anything like this. Hopefully this is the right thread for it. I got some juice from my brother (out of town). It produces a ton of vapor. The store where he bought says it has no VG, only PG, and possibly some water and or ethyl alcohol, and flavoring (alcohol may be in the flavoring?, they won't say). I'm curious how they get so much vapor without VG? Is it the alcohol or water. If so... what are the downsides to doing this for my own mixes? Thanks!