The Enzymatic mb12 has mannitol so I can't use it.
The Natural Factors mb12 1000mcg sublingual seems to be working for me. Nothing measurable, but I believe both my mental and physical energy levels are slightly higher. I have no other product to compare its' effect against.
I've been trying the Anabol Dibencoplex sublingually as Freddd suggests.. with mixed results. Some of it does what you'd expect (dissolves to redish pink) but the white powder doesn't dissolve - I assume this is the "other ingredients" and/or the boron. I've gone up to 1 hour which is about all I can stand before washing it down. If the red is the cobamamide then it doesn't seem to be released slowly, but immediately, in which case I'm not sure sublingual makes sense.