Drug & supplement interaction

Iron + Moxifloxacin

Moxifloxacin brand name: Avelox.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Iron has a moderate interaction with Moxifloxacin. Iron might decrease levels of quinolone antibiotics by reducing their absorption.

Read the full interaction report
SeverityModerate
LikelihoodProbable
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Iron and Moxifloxacin

Here is the interaction we found between these two, with the evidence behind it.

Moderate

QUINOLONE ANTIBIOTICS

Why this applies to Moxifloxacin

Moxifloxacin falls under QUINOLONE ANTIBIOTICS — the group Iron interacts with.

Iron might decrease levels of quinolone antibiotics by reducing their absorption.
Advise patients to separate quinolone antibiotics and iron doses by at least 2 hours. Iron decreases the absorption of quinolones due to formation of insoluble complexes in the gastrointestinal tract.
Severity Moderate Likelihood Probable Evidence D

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version: if you swallow your iron supplement and your moxifloxacin (Avelox) too close together, the iron can grab onto the antibiotic in your stomach and form a clump that your body can't absorb well. The worry isn't extra side effects, it's the opposite. You may end up with less moxifloxacin in your bloodstream than your infection needs, which could mean the antibiotic doesn't fully knock out the bacteria.

The good news is this is easy to manage. The usual advice is to separate the two doses by at least 2 hours, taking the moxifloxacin first and the iron later (or the other way around with enough of a gap). This is based on how the drug behaves chemically rather than big patient studies, but it's a sensible, well-accepted precaution. Run your exact timing by your pharmacist to be sure.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Tatro DS, ed. Drug Interactions Facts. Facts and Comparisons Inc., St. Louis, MO. 1999.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Iron Also Interacts With Other Medications

Iron has 78 moderate, 1 minor known drug interactions in our database — the Moxifloxacin one above is one of them. If you take anything else, check it against the full list below.

Moderate 78 Minor 1 No known interaction 2,751 (incl. Moxifloxacin)
Taking anything else?

Check Another of Your Medications Against Iron

Covers the 2,830 medications we’ve checked against Iron. Pick one to open its full report.

From our Q&A

Questions About Iron or Moxifloxacin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Iron or Moxifloxacin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Moxifloxacin

This page covers Iron only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Moxifloxacin page lists 155 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Apple (major), Arsenic (major) and Asarabacca (major).

By severity: 13 major · 121 moderate · 21 minor.

From our pharmacist’s overview on the Moxifloxacin page

“The supplement list for moxifloxacin (Avelox), a fluoroquinolone antibiotic, deserves genuine care, and the everyday items are the surprising part. Ordinary juices, apple, grapefruit, and sweet orange among them, block a transporter the drug needs for absorption and can cut how much reaches your blood, which for an antibiotic means the…”

Reviewed by 2 · Jul 18, 2026

Open the Moxifloxacin interaction page

One more smart check

Taking Iron as Part of a Dietary Supplement Product? Check It for Interactions

We hold 16,325 real supplement products containing Iron, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Iron. Your product may carry other ingredients that interact with Moxifloxacin too, on top of Iron — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Iron and Moxifloxacin Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Iron
Top 1%

#14 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Moxifloxacin
Top 25%

#656 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Iron

What is Iron?

  • Iron-deficiency anemia
  • Low iron stores during pregnancy
  • Fatigue from iron deficiency
  • Heavy menstrual blood loss
  • Restless legs syndrome (with low iron)

Iron is an essential mineral your body needs to make hemoglobin and carry oxygen in the blood. Supplements are mainly useful for treating or preventing iron deficiency and iron-deficiency anemia, ideally after a blood test confirms you are low. Because too much iron can be harmful, take it only when needed and under the guidance of a pharmacist or doctor.

Read the full Iron monograph & all interactions
Medication

About Moxifloxacin

What Is Moxifloxacin Used For?

Brand name: Avelox

Moxifloxacin tablets and intravenous (IV) injection are approved for adults 18 and older to treat bacterial infections including community-acquired pneumonia, uncomplicated and complicated skin infections, complicated abdominal infections, plague, acute bacterial sinusitis, and acute bacterial flare-ups of chronic bronchitis. Note: moxifloxacin should only be used for sinusitis and chronic bronchitis flare-ups when no other antibiotic option is available, due to the risk of serious side effects.

Moxifloxacin ophthalmic solution (eye drops) — including the brand Vigamox — is a separate, topical formulation used only in the eye to treat bacterial conjunctivitis (pink eye) caused by susceptible bacteria. The eye drop form is not used for body-wide infections.

See full Moxifloxacin drug information
Keep checking

Other Drugs & Iron

Browse every other medication we’ve checked against Iron — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
78Moderate
1Minor
2,750No known interaction
78 Moderate 1 Minor 2,750 No interaction
Moderate

78 interactions

Showing 60 of 78 moderate interactions — see all 78 on the Iron page.

Minor

1 interaction

No interaction 2,750 drugs checked — show the list

We also checked Iron against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,750 medications checked with no known interaction — see the full Iron list.

See the full Iron interactions page
See every supplement checked against Moxifloxacin, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Iron monograph › Uses, safety, and every drug interaction in one place Moxifloxacin supplement interactions › Every supplement checked against Moxifloxacin, ranked by severity Moxifloxacin drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Iron and Moxifloxacin Together: Common Questions

Can you take Iron with Moxifloxacin?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Iron and Moxifloxacin interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Moxifloxacin and Iron?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.