I am hetero C677T and A1298C. I am overly sensitive to oral meds and supplements so doc put me on transdermal methyl B formulation. I have been using it for 3 weeks. It has been trial and error with the amount but finally felt I had found a comfortable start-up amount. A few days ago, I applied my regular dose and shortly after began experiencing palpitations, restless energy/anxiety and shortness of breath. Since then, I have tapered down to almost nothing. Palpitations are gone along with the anxiety. However, shortness of breath remains. After reading many posts on this site, I realize it could be low potassium because of methylation kicking-in. Three months ago, my potassium level was at the lower end of “normal” at 3.9 (3.5-5.3). I have ramped-up my potassium intake with coconut water and bananas. I also eat a potato every evening. However, the increase in potassium doesn’t seem to help. I started taking a 99 mg potassium supplement yesterday and could tell a definite difference after an hour or so but still felt more was needed. I've taken 3 of the supplements throughout the day today and my breathing was even better. Obviously, the potassium seems to be the problem I do use transdermal magnesium daily. How will I know when I've reached the optimal level of potassium and will I need to stay on it permanently or just until methylation regulates?