About this information
This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.
Cautions with other medicines
Cyanocobalamin is usually safe to take with other medicines, including painkillers.
Some medicines may reduce the amount of cyanocobalamin you absorb from the tablets or from the food you eat. This will not usually have a noticeable effect. However, tell your doctor or pharmacist if you're taking:
- metformin for diabetes
- antacids like Gaviscon
- H2 blockers like ranitidine, cimetidine, famotidine or nizatidine
- proton pump inhibitors (PPIs) like lansoprazole, omeprazole, pantoprazole or rabeprazole
View the original NHS website page ↗. Refreshed 19 August 2026.
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