I was wondering why I feel anxious and shaky after I take Cyanocobalamin, but I do not get that bad effect when I take Methylcobalamin? Both tablets are the same dose (1,000 mg).

I have both forms of B-12 in my house. The Cyanocobalamin tablet (Nature's Bounty) dissolves very fast under my tongue, and then for several hours afterwards I feel rather anxious and shaky. Eventually the feeling dissipates but I don't like it. It reminds me of how I used to feel when I got allergy shots laced with epinephrine, or how I feel if I have caffeine. I have tried it several times, both on an empty stomach and not. It's always the same effect.

The Methylcobalamin (NOW, Jarrow -- I have both) has absolutely no side effect for me, and I feel fine after dissolving that under my tongue. (The Jarrow one takes a really long time to dissolve).

Any idea why one would make me feel anxious and the other doesn't? I know that the Methyl variety is absorbed better by the body, but that's about all I know about the difference between the two.

Thank you!