Supplements and Ciprofloxacin.
Ciprofloxacin, sold under the brand name Ciproxin, is classified under "quinolone" in the BNF.
Ciprofloxacin is an antibiotic, usually taken as a short course, and the supplement questions people ask most when given one have reassuring answers. Probiotics are fine to take alongside it and lower the chance of antibiotic-related diarrhoea: space a bacterial probiotic, most Lactobacillus or Bifidobacterium products, about two hours from your dose, while Saccharomyces boulardii, which is a yeast, can be taken at the same time. Most everyday vitamins and minerals have no significant interaction with a short antibiotic course, so a daily multivitamin, vitamin D or vitamin C is generally not a concern. The combinations that genuinely matter are listed below with their evidence, and they tend to be specific: supplements that thin the blood, serotonergic supplements stacked on certain antibiotics, and supplements that are really a prescription drug in disguise, such as red yeast rice, which contains the statin lovastatin. One timing rule applies to Ciprofloxacin specifically: calcium, iron, magnesium and zinc bind it in the gut and reduce how well it is absorbed, so separate any of those supplements from your dose by about two hours. The sensible step in every case is to tell your pharmacist what you already take, which is free at any UK community pharmacy.
Below are the 6 documented pairs we have explicitly assessed against Ciprofloxacin in the Distil database: 5 amber and 1 green. The pairs cluster around 2 mechanisms: Mineral chelation (absorption) and Probiotic timing with antibiotics. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not on this list is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by supplement, and the missing-item form at the bottom of the page routes any uncatalogued supplement into our next curation pass.
Documented interactions
Mineral chelation (absorption)
Calcium binds to ciprofloxacin in the gut and can reduce how much antibiotic you absorb by around 40 percent, which may let an infection persist. Take ciprofloxacin at least two hours before, or six hours after, any calcium supplement.
Iron binds to ciprofloxacin in the gut and can cut the amount of antibiotic you absorb by more than half, which may let an infection persist. Take ciprofloxacin at least two hours before, or six hours after, any iron supplement.
Magnesium can bind to ciprofloxacin in the gut and sharply reduce how much antibiotic you absorb, which may let an infection persist. Take ciprofloxacin at least two hours before, or six hours after, any magnesium supplement.
Magnesium can bind to ciprofloxacin in the gut and sharply reduce how much antibiotic you absorb, which may let an infection persist. Take ciprofloxacin at least two hours before, or six hours after, any magnesium supplement.
Zinc can bind to ciprofloxacin in the gut and reduce how much antibiotic you absorb, which may let an infection persist. Take ciprofloxacin at least two hours before, or six hours after, any zinc supplement.
Probiotic timing with antibiotics
These are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your ciprofloxacin dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope (food-supplement interactions only; for drug-drug interactions, the BNF is authoritative). Use the checker below to surface any supplement, and submit a missing item if you take something we have not catalogued.
For adults over 18.
This tool gives evidence-graded information, not medical advice. Always discuss changes with your GP, pharmacist, or specialist before making them, especially if you take any medication, are pregnant, breastfeeding, or have a serious health condition.
How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
Read the full methodologySomething missing?
If a supplement or medication you take isn't in our autocomplete, tell us. We go through what people flag every week and add what's missing.