Another thing to consider is the nicotine content. I had the same problem until just recently. I'm apparently sensitive to nicotine in my juice. All the juices at 6mg and some at 3mg would make me cough. I've recently mastered DIY for my juice so I use 2.5mg and no more coughing. That's not quite true, I now run my power up until I start coughing and then back off a little. Works much better for me. Just something else to consider.