Welcome to Just Answer and thanks for your question. This gets a bit complicated. Vitamin B12 is actually a mixture that the body converts into a form that it can use. One of the most useful forms is methycobalamin, which is included in Cerefolin NAC. Along with methycobalamin, the pill contains L-methylfolate (another B vitamin) and N-acetylcysteine (to improve the brain neurotransmitter acetylcholine). Dozens of studies have shown that oral B12 tablets are just as effective as injections (and many times cheaper to use).
That's right. Studies have focused on plain B12 tablets available at any drug store, but there is no reason to think that the research would not extend to Cerefolin NAC as well.