I've been vaping for about 5 weeks and had a checkup. My doctor strongly advised me to get off vaping and said that although it was better than smoking, that it wasn't much better. Before the appointment I had been getting some ejuice in my mouth and it made my tongue turn a brown color (has gone away since) and some small craters on my tongue. I have since done a better job of cleaning my cartridge after I fill it and am thinking of lowering my nicotine from 18 to 12. Just wanted to know what your doc says about vaping