Cyanocobalamin Injection, USP is a sterile solution of cyanocobalamin for intramuscular or subcutaneous injection. Each mL contains 1,000 mcg cyanocobalamin.

Each vial also contains sodium chloride, 0.9%. Benzyl alcohol, 1.5%, is present as a preservative. Sodium hydroxide and/or hydrochloric acid may have been added during manufacture to adjust the pH (range 4.5-7.0).

Cyanocobalamin appears as dark red crystals or as an amorphous or crystalline red powder. It is very hygroscopic in the anhydrous form, and sparingly soluble in water (1:80). It is stable to autoclaving for short periods at 121° C. The vitamin B12 coenzymes are very unstable in light.

The chemical name is 5,6-dimethyl-benzimidazolyl cyanocobamide; the molecular formula is C₆₃H₈₈C0N₁₄O₁₄P. The cobalt content is 4.34%. The molecular weight is 1355.39.