Iron

Which medicines interact with iron?

Updated 9 Nov 2026

Short answer

Iron lowers the absorption of levothyroxine, a thyroid hormone medicine, and some of its labels advise a gap of 4 hours.[1] Iron also lowers the absorption of levodopa, a medicine for Parkinson's disease and restless legs.[1] Proton pump inhibitors such as omeprazole lower stomach acid, and people with iron deficiency who take them can respond less well to iron.[1]

Calcium might lower iron absorption, so experts suggest taking calcium and iron supplements at different times.[1] People who take a medicine every day should talk about their iron with a doctor or pharmacist.[1]

Sources (1)

  1. Iron: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov

More about iron

What is iron?Which foods contain iron?How long does it take for iron supplements to work?What is iron used for?What are the signs of iron deficiency?Is iron safe?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.