Can you take Metformin and Vitamin B12 together?
Yes — but there is one thing worth knowing.
Metformin and Vitamin B12 can be taken together — there is one detail worth knowing first.
Why these two interactSources for why these two interact: Jumps to this entry in the sources and references list at the end of the page.
Long-term metformin use is associated with reduced B12 absorption and lower serum B12.
What to do about itSources for what to do about it: Jumps to this entry in the sources and references list at the end of the page.
Monitor B12 annually; supplement 500–1000 mcg/day if low.
TimingSources for timing: Jumps to this entry in the sources and references list at the end of the page.
No fixed separation window applies here. Keep the timing consistent day to day so any effect is easy to spot.
The two items in this pair
Metformin
- Category:
- medication
- Typical timing:
- with_meal
- With food:
- with_food
- Half-life:
- 6.2 h
Check your whole routine, not just this pair
One pair rarely tells the whole story. DoseRoutine checks every combination in your stack at once — supplements, TRT, peptides, GLP-1s and prescriptions — and schedules the doses so timing conflicts like this one are handled automatically.
Frequently asked
Sources cited on this page
Specific documents referenced by the numbered markers above.
- Association between metformin and vitamin B12 deficiency in patients with type 2 diabetes(opens in a new tab)PubMed — National Library of Medicine · pubmed.ncbi.nlm.nih.gov/37273250/
- Metformin hydrochloride — FDA prescribing information(opens in a new tab)DailyMed — U.S. National Library of Medicine · dailymed.nlm.nih.gov/dailymed/drugInfo.cfm
Verify at
This assessment is mechanism-based. These publisher search links let you check it against the current evidence — they are not citations, so they are not numbered.
- PubMed: Metformin + Vitamin B12(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed label: Metformin(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- DailyMed label: Vitamin B12(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
Related combinations
Educational information only, not medical advice. DoseRoutine does not diagnose or treat. Talk to your prescriber before starting, stopping or combining anything — especially if you take prescription medication or are pregnant or breastfeeding.