I've had non-stop palpitations and shortness of breath since stopping methyl transdermal B a month ago. The methylation process had obviously started up due to the symptoms I was having. It evidently was also enough to send me from hypothyroid to hyperthyroid. I had to reduce my dosage of natural thyroid just so I could sleep at night. That helped tremendously. However, I am still having rapid palpitations all day 24/7. I completely stopped taking my thyroid med for a couple of days to see if that would help. It didn't make a difference in the palpitations so I resumed taking it. I know it has to be my potassium. Whenever I take potassium capsules, my breathing gets better and palps aren't as bad. However, I can't seem to take enough of them to get complete relief. They start to hurt my stomach after a while. I went to my health food store and bought potassium chloride in the powdered form. That's the only powdered form they had or any store around here has. Anyway, I mixed 3 doses (1095mgs) with water and powdered coconut water. I can tell it helps but still having palps. Breathing is much, much better. I'm currently taking B12 Hydroxy 1000mcg per day. Should I cut back on the B12 dosage for now? I know it's different for everyone, but how will I know when I reach the correct amount of potassium for me daily? I also take 1000iu's of Vit D, 500mgs of calcium, and several sprays of transdermal magnesium oil throughout the day. The palps and shortness of breath are driving me crazy. The palps keep me up at night. I use an inhaler so I can tolerate the shortness of breath.