I've been vaping for 3+ years and never had any physical reactions/problems with commercial e-liquid, other than the price! I'm pretty new to DIY (2 months) and feel like I'm starting to get a "bad" reaction to my eliquid. I was fine for the first month and a half, but every night for the last 10 days or so I get a sore throat and congestion, and wake up the same way. By around noon I seem to be fine. Wash, rinse, repeat. I use flavorings from all the common name brands: CAP, TPA, FA, FLV, INW, LA, etc., and I don't use excessive amounts in recipes (usually around 8%-12%). My nic is 100mg/ml VaporsTek, and most of my mixes are 3mg. My PG/VG is Nature's Oil from Bulk Apothecary. I assume it's not the flavorings since they are the same the commercial guys use, which leaves the nic and PG/VG. Has anyone ever had a sensitivity or reaction they were able to track to specific ingredients? Has PG/VG from a specific brand caused anyone problems? Same for nic?