With the exception of some tobacco flavors, the vast majority of e-juice flavorings are re-purposed food flavorings. But the advantage of buying something that is specifically marketed as e-juice flavoring is that you can (usually) assume that others have already vaped it before you, and not gotten sick or had other obvious problems. But even that is only true in the short term, and no one can really say that any of the flavorings we use has no possibility of causing problems a few years down the road. Most of us shrug that off knowing that we used to inhale really, obviously nasty stuff to satisfy our nicotine habits.
So the fact is that what you have may or may not be any worse than flavorings that are sold for DIY e-juice, but do you want to be the first guinea pig? Anytime the word "oil" is used in the ingredients list, that sets off some alarm bells because lipids are definitely not something you want in your lungs. But many of the flavor extractions are called oils, but do not contain lipids. In that sense, they would be more accurately defined as essences or resins, but the term oil is used somewhat loosely when it comes to flavorings. Artificial colorings are another potential cause for concern, although I expect that some pre-made juice and perhaps some flavorings contain one or more. But again, do you want to be the guinea pig? If so, let us know how it works, assuming you survive to tell the tale.
