About this information
This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.
Who can take cyanocobalamin
Most adults and children can take cyanocobalamin.
Who may not be able to take cyanocobalamin
Cyanocobalamin is not suitable for everyone. To make sure it's safe for you, tell your doctor before starting to take it if you:
- have ever had an allergic reaction to cyanocobalamin or any other medicine
- have an allergy to cobalt
View the original NHS website page ↗. Refreshed 19 August 2026.
Licensed under the Open Government Licence v3.0 ↗. MyPHU is independent and is not endorsed by the NHS.