Different batches from the same source doesn't mean it's been cut with something different. You just can't know what your ingesting. Every time you get a new batch, start out with a tiny, little bit to test...This prevents an OD as well as let's you know what you've got.
FYI, if by "Ingesting" you mean you swallowing it, you might want to change your route up, because believe it or not, it's the worst way to do it as far as negative physical damage. It eats the lining of your stomach and entire GI tract away, including your throat, and stomach ulcers are really common and develop quickly...and at the same time, it's being basically time-released into your blood stream over hours, so burning and aching all over for quite a while is not uncommon. And if it's cut with something caustic or any straight chemicals at all, that's a long time for it to eat away at your body, hence the burning and aching in the extremities...
