My B12 is just under 300 which shows a deficiency and I always have rapid heart beat.(along with Anxiety, agitation, and tiredness due to my heart beating so fast all the time). So eventhough I have a fast pulse, I always look tired. Here is what I have tried so far: Hydroxy 12 Pills - Experience : Made me sleep better , I felt less agitated and calmer the next day, but kinda tired. I did smile and feel happy for no reason though which was nice for a change! I had to stop it because like many other pills and tablets, it gave me a headache after 2 days of use, MethylB12 Injection- Experience: No headache as I never get headache from injections. But did not improve my sleep much. My agitation was 30% better but not as much as Hydroxyb12 If it makes any difference, I have 3 kinds of COMT+/+ ( rs4633, rs4646312, and rs4680) I will be seeing my Dr. in 2 weeks and I am debating if I should ask him to give me HydroxyB12 Shots to see if I can get the benefits I got from the pill without the headache, but after reading some of the posts here about B12 I thought it's best if I ask. Which kind of B12 do you think is best for my case? Thanks so much and Happy New Year!