Fluoroquinolones and tetracyclines chelate iron
Ciprofloxacin, doxycycline, minocycline, and other fluoroquinolones and tetracyclines form insoluble complexes with iron, dramatically reducing absorption of both the drug and the mineral.
Take iron 2 hours before or 6 hours after these antibiotics to avoid reducing the antibiotic's effectiveness.
Separate by at least 2 hours before or 6 hours after antibiotic
Fluoroquinolones and tetracyclines chelate iron. Take iron 2 hours before or 6 hours after these antibiotics to avoid reducing the antibiotic's effectiveness.
Separate by at least 2 hours before or 6 hours after antibiotic
This interaction is rated “Warning” by Formulate. Ciprofloxacin, doxycycline, minocycline, and other fluoroquinolones and tetracyclines form insoluble complexes with iron, dramatically reducing absorption of both the drug and the mineral.
Studies from our registry that mention antibiotics or iron. Each links to the primary source and the other Formulate pages citing it.
Mentions iron · 2017
Oral iron supplements increase hepcidin and decrease iron absorption from daily or twice-daily doses in iron-depleted young women
Stoffel NU, Cercamondi CI, Brittenham G, et al. · Blood
Landmark absorption study showing iron supplements taken daily (or twice-daily) trigger hepcidin elevation that blocks subsequent absorption — supporting alternate-day dosing as more efficient for iron repletion.
Mentions iron · 2010
Iron bioavailability and dietary reference values
Hurrell R, Egli I · American Journal of Clinical Nutrition
Reviews enhancers (vitamin C, meat) and inhibitors (phytate, polyphenols, calcium) of non-heme iron absorption, providing the mechanistic basis for pairing iron with vitamin C and separating it from tea/coffee.
Mentions iron · 2000
Prediction of dietary iron absorption: an algorithm for calculating absorption and bioavailability
Hallberg and Hulthén · American Journal of Clinical Nutrition
Foundational model for non-heme iron absorption factoring vitamin C, phytates, tannins, and calcium interactions.
Other interactions to know
Calcium significantly reduces iron absorption
Iron reduces levothyroxine absorption
Zinc and iron compete for absorption
Antacids significantly reduce iron absorption
PPIs reduce non-heme iron absorption
Antibiotics kill probiotic bacteria if taken together
Phytates in fiber reduce non-heme iron absorption
Vitamin C dramatically enhances iron absorption
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Medical disclaimer. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.
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