Does Ferrous Sulfate Interact With Levothyroxine?
Drug or Drug Class Effect Phosphate Binders (e.g., calcium carbonate, ferrous sulfate, sevelamer, lanthanum) Phosphate binders may bind to levothyroxine.
Severity: Minor
Severity basis: drug interactions section. Combining Ferrous Sulfate (Oral iron supplement) and Levothyroxine (Thyroid hormone) is classified as a minor interaction.
What to Do
This is generally a minor interaction, but review it with your pharmacist to be sure it is safe for you.
From the FDA Label
Drug or Drug Class Effect Phosphate Binders (e.g., calcium carbonate, ferrous sulfate, sevelamer, lanthanum) Phosphate binders may bind to levothyroxine.
Source: FDA structured product labeling (set_id 008de8fd-150f-4022-8ccb-c8bfa94875c7).
Check these against your full medication list in our free Interaction Checker
This information is educational — not medical advice.
This page is provided for general educational purposes and summarizes publicly available data from sources such as the U.S. Food & Drug Administration. It is not a substitute for the judgment of a licensed clinician and should not be used to start, stop, or change any medication. It may be incomplete or out of date, and individual circumstances vary. Always talk with your prescriber or pharmacist about your specific medications and health conditions. If you think you may have a medical emergency, call 911.
Other Ferrous Sulfate Interactions
Other Levothyroxine Interactions
- Levothyroxine + Amitriptyline(moderate)
- Levothyroxine + Carbamazepine(moderate)
- Levothyroxine + Dexamethasone(moderate)
- Levothyroxine + Alendronate(minor)
- Levothyroxine + Amiodarone(minor)
- Levothyroxine + Aspirin(minor)
- Levothyroxine + Furosemide(minor)
- Levothyroxine + Liothyronine(minor)
- Levothyroxine + Nifedipine(minor)
- Levothyroxine + Phenytoin(minor)
- Levothyroxine + Propranolol(minor)
- Levothyroxine + Rifampin(minor)
- Levothyroxine + Semaglutide(minor)
- Levothyroxine + Sertraline(minor)
- Levothyroxine + Sucralfate(minor)