--as it is a complex formulation of B-vitamins but one can get all these separately and over the counter--and besides, when megadosing B12 in the 1000-5000mcg range generally the best thing to do is take that apart from the others, on an empty stomach, as the cobalamin molecule, being the largest one the body regularly uses, is quite easy to interfere with the absorption of.

When I was at the Neuropathy Summit in DC in December 2010 there were numerous Metanx representative there that I grilled incessantly about vitamin absorption/interaction, and it turned out they knew little about absorption/interaction issues. Maybe I should have expected they would be less than knowledgable--they were reps, after all--but still.

I suppose Metanx is an option for those who can't take multiple pills at different times AND whose insurance will reimburse well. But many people have found it cheaper to order their B12, B-complex, folate, etc. from one of the many decent on-line sources, and take their pills at different times for maximum effect.