Compared to other types of vitamin B12 supplements, the sublingual method doesn't seem to be any more or less effective. A study from 2006 didn't find any difference in effectiveness between sublingual and oral vitamin B12 supplements (Yazaki, 2006).

Which form of B12 is better absorbed?

Methylcobalamin. Methylcobalamin is the most bio-available type of Vitamin B12 which means the body absorbs it more easily. Naturally occurring, it is found in animal-based foods such as meat, fish, milk and eggs so is readily available in many people's daily diet.

How long does it take sublingual B12 to work?

B12 injections work quickly; they are the most effective way for your body to absorb Vitamin B12. Within 48 to 72 hours, your body will begin to make new red blood cells.