Most of our products that include vitamin B12 contain only the active forms (usually both): adenosylcobalamin and methylcobalamin. The only exception to this is this standalone formula, Hydroxo B12 lozenge, which contains the hydroxocobalamin form.
Cyanocobalamin is not an active form of B12. This form of B12 is the least expensive for companies to manufacture, so it is in many of the “bargain” brands on the market. This is B12 attached to a cyanide molecule. It is not as well absorbed as the other popular forms of B12 supplements, and the process it goes through within the body also requires detoxifying and excreting the potentially harmful cyanide molecule. Complications can arise if too much cyanide accumulates in the body from high doses of this form taken over long periods of time.*