Drug interactions
Cyanocobalamin + Metformin
Severity: Moderate
Cyanocobalamin and Metformin: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Long-term metformin use is associated with reduced vitamin B12 absorption and lower serum levels. Supplementation with cyanocobalamin can correct this, so the interaction mainly concerns metformin lowering B12 status.
What this interaction means in plain words
Cyanocobalamin and Metformin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Cyanocobalamin belongs to Miscellaneous; Metformin belongs to Endocrine.
Why it happens
Metformin impairs calcium-dependent ileal absorption of the B12-intrinsic factor complex.
What to do
Measure vitamin B12 periodically in long-term metformin users, particularly with anemia or neuropathy. Supplement if deficient.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Cyanocobalamin and Metformin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Metformin
Other interactions of Cyanocobalamin
Frequently asked questions
Can I take Cyanocobalamin with Metformin?
MediHelp rates the interaction as moderate. Cyanocobalamin and Metformin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Long-term metformin use is associated with reduced vitamin B12 absorption and lower serum levels. Supplementation with cyanocobalamin can correct this, so the interaction mainly concerns metformin lowering B12 status.
How serious is the interaction between Cyanocobalamin and Metformin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Measure vitamin B12 periodically in long-term metformin users, particularly with anemia or neuropathy. Supplement if deficient.
What other medicines interact with Metformin?
MediHelp also lists interactions of Metformin with, for example, Contrast media, Diatrizoate meglumine / diatrizoate, Diatrizoate. The full list is on the Metformin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
