How Food, coffee, calcium, iron, and high-fiber foods with levothyroxine Affects Your Medications
Take levothyroxine on an empty stomach with water, 30–60 minutes before breakfast, and separate it from calcium or iron supplements by at least 4 hours.
This interaction is generally considered moderate in severity.
How It Happens
Food (especially coffee, calcium, iron, and high-fiber foods) reduces absorption of levothyroxine, which can make thyroid treatment less effective.
What to Do
Take levothyroxine on an empty stomach with water, 30–60 minutes before breakfast, and separate it from calcium or iron supplements by at least 4 hours.
Medication Classes Affected
Specific Medications to Watch
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 It may be incomplete or out of date, and individual circumstances vary.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.