From the Manufacturer:
Supplements like multivitamins often contain B-12 but usually it is not absorbed well in this form. Injections are effective but require a doctor’s office visit and are painful. Researchers have concluded that sublingual (“under the tongue”) delivery is a very effective and inexpensive means of delivering the vitamin. When placed under the tongue or between the cheek and gum, the lozenge dissolves and releases B-12 into the blood stream in as little as 15 minutes. Vitabase Methyl B-12 uses the coenzyme form of B-12, methylcobalamin, the most bio-available and active form of B-12. Most supplements (including one widely advertised on TV) use cyanocobalamin which the liver must convert to methylcobalamin.