Medication·Interactions & depletion·Reviewed June 9, 2026
Famotidine interactions.
Famotidine has 4 documented interactions in the NutriStack database. Prolonged use is also associated with lower Vitamin B12. The full interaction list, depletion table, and replacement suggestions are below. None of this is a substitute for your prescriber's advice.
Famotidine at a glance.
A quick, data-grounded summary. The full tables are below.
Famotidine has 4 documented interactions in the NutriStack database. Prolonged use is also associated with lower Vitamin B12. The full interaction list, depletion table, and replacement suggestions are below. None of this is a substitute for your prescriber's advice.
Substances that interact with famotidine.
Every supplement and medication in the NutriStack database with a documented interaction with this drug, highest-severity first. Open any pair for the mechanism and sources.
| Substance | Interaction | What happens |
|---|---|---|
| Calcium | Caution | Famotidine reduces gastric acid and can lower the absorption of calcium carbonate, which depends on acid to dissolve. The fracture-risk signal is... details → |
| Iron | Caution | Famotidine can reduce absorption of oral iron, especially non-heme iron salts that require gastric acid. In the Kaiser study, two or more years of... details → |
| Vitamin B12 | Caution | Long-term famotidine therapy can lower vitamin B12 status by reducing acid-pepsin-dependent release of B12 from food. The Kaiser case-control study... details → |
| Methylcobalamin | Synergy | Methylcobalamin (a free coenzyme form of B12) does not require gastric acid for absorption, making it a reliable supplemental B12 source for... details → |
What famotidine can deplete.
Nutrients this medication is associated with lowering over time, with the mechanism, a suggested replacement where one applies, and the biomarker to monitor. Discuss any replacement with your prescriber first.
| Nutrient | Severity | How it happens | Replace with | Monitor |
|---|---|---|---|---|
| Vitamin B12 | Mild | Chronic H2 receptor blockade reduces gastric acid needed to release food-bound vitamin B12 before intrinsic factor binding. | Methylcobalamin | Serum B12 + methylmalonic acid |
The full famotidine profile.
Uses, typical dosing, side effects, and the cited evidence for this medication.
Common famotidine questions.
Quick answers drawn from the tables above.
What interacts with Famotidine?
In the NutriStack database, Famotidine has 4 documented interactions. The most notable include Calcium, Iron, Vitamin B12, and Methylcobalamin. Check any specific combination before taking it and confirm with your prescriber.
Does Famotidine deplete any nutrients?
Famotidine is associated with lowering Vitamin B12 with prolonged use. Useful biomarkers to monitor include Serum B12 + methylmalonic acid. Ask your prescriber before adding any replacement supplement.
Is it safe to take Calcium with Famotidine?
NutriStack classifies the Calcium and Famotidine pairing as caution: Famotidine reduces gastric acid and can lower the absorption of calcium carbonate, which depends on acid to dissolve. The fracture-risk signal is weaker for H2 blockers... If you take famotidine regularly, prefer calcium citrate, which absorbs well without gastric acid. If using calcium carbonate, take it with a meal... Always confirm with your prescriber.
Check your whole stack
See how famotidine fits your supplements.
NutriStack screens your full routine for interactions and depletions, and updates the moment you change it.