Unfortunately I have to see several specialists for post cancer surgery exams. My Cardiologist and Oncologist both stated that they were not concerned with nicotine. The tars and carcinogens of analogs made it essential I quit smoking after 40 years. Now at each exam they say my lungs are clear. I do MRI and Cat Scan every three months since 2011. Nothing showing up. I started vaping in 2010. IMO just avoid flavors and juices that can't provide SDS and Labs. Sorry this ran so long.