Cyanocobalamin (B12) Injection 1000 mcg mL, Multiple Dose Vial 30 mL McGuff Hydroxocobalamin (Vitamin B12): Uses, Alternatives, Side Effects & More GoodRx Oh My, There is Cyanide in B12 Supplements. Really. Office for Science and Society McGill University Cyanocobalamin vs. Methylcobalamin: What's the difference? Both are forms of vitamin B12, essential for energy, brain health, and red blood cell production. But here's the key: Cyanocobalamin is synthetic and needs