I tried liquid, sub lingual tabs, etc. I absolutely did not get the benefit from other forms at the level I get from the injected form. I use a very tiny insulin syringe into the upper buttock. It's a very easy and quite painless injection. Occasionally, I add 25 IU B6. I really feel that injecting is a far more reliable method as it is not at the mercy of the contents of one's stomach.
I believe that the dose translates into .5 grams. I mail order the B12, no prescription needed.