Interaction reference
GLP-1 receptor agonists with Vitamin B12
Vitamin B12 supplementation is common on GLP-1 therapy, particularly for patients also taking metformin (which lowers B12). No interaction with the GLP-1 itself.
No interaction with your GLP-1 — but if you also take metformin, B12 monitoring is worth asking your prescriber about.
Also known as: cobalamin, methylcobalamin, B-complex
Per-GLP-1 breakdown
- Wegovysemaglutide 2.4 mgNo documented interaction
Mechanism: B12 absorption is not affected by GLP-1 receptor agonists. The relevant interaction is with metformin, which can reduce B12 over time; many GLP-1 users also take metformin.
What to do: No restriction. If you take metformin alongside your GLP-1, ask your prescriber to check B12 annually. Reduced appetite on GLP-1s can lower dietary B12 intake, so a B-complex is reasonable insurance.
- ZepboundtirzepatideNo documented interaction
Mechanism: B12 absorption is not affected by GLP-1 receptor agonists. The relevant interaction is with metformin, which can reduce B12 over time; many GLP-1 users also take metformin.
What to do: No restriction. If you take metformin alongside your GLP-1, ask your prescriber to check B12 annually. Reduced appetite on GLP-1s can lower dietary B12 intake, so a B-complex is reasonable insurance.
- OzempicsemaglutideNo documented interaction
Mechanism: B12 absorption is not affected by GLP-1 receptor agonists. The relevant interaction is with metformin, which can reduce B12 over time; many GLP-1 users also take metformin.
What to do: No restriction. If you take metformin alongside your GLP-1, ask your prescriber to check B12 annually. Reduced appetite on GLP-1s can lower dietary B12 intake, so a B-complex is reasonable insurance.
- MounjarotirzepatideNo documented interaction
Mechanism: B12 absorption is not affected by GLP-1 receptor agonists. The relevant interaction is with metformin, which can reduce B12 over time; many GLP-1 users also take metformin.
What to do: No restriction. If you take metformin alongside your GLP-1, ask your prescriber to check B12 annually. Reduced appetite on GLP-1s can lower dietary B12 intake, so a B-complex is reasonable insurance.
- FoundayoorforglipronNo documented interaction
Mechanism: B12 absorption is not affected by GLP-1 receptor agonists. The relevant interaction is with metformin, which can reduce B12 over time; many GLP-1 users also take metformin.
What to do: No restriction. If you take metformin alongside your GLP-1, ask your prescriber to check B12 annually. Reduced appetite on GLP-1s can lower dietary B12 intake, so a B-complex is reasonable insurance.
Sources
- Vitamin B12 — fact sheet for health professionals (opens in a new tab) — NIH Office of Dietary Supplements