What is in e-liquid? And what is it that makes all that vapor? There are two ingredients that make the vapor. Those two are propylene glycol and vegetable glycerin. The other ingredients are nicotine and flavoring. The nicotine and flavoring account for about 8% to 10% of the total composition of e-juice. The rest of the liquid is the propylene glycol, PG, and vegetable glycerin, VG.
Vegetable Glycerin (VG)
Propylene Glycol (PG)
As for the nicotine in e-liquid, that is typically pharmaceutical grade and extracted from tobacco plants. Because the nicotine in vaping liquids is extracted from tobacco plants, the FDA has classified electronic cigarettes as a tobacco product.