Is Calcium Safe with Ciprofloxacin?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Take Ciprofloxacin at least 2 hours before or 6 hours after calcium supplements or calcium-fortified foods.
Why this interaction occurs
Calcium ions form insoluble chelate complexes with ciprofloxacin in the gastrointestinal tract, reducing oral bioavailability by up to 50%, potentially leading to treatment failure.
Evidence
Evidence level: strong.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 86,830 reports mentioning Ciprofloxacin. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Ciprofloxacin + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Calcium interactions → · All Ciprofloxacin interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.