Drug & supplement interaction

Iron + Zoledronic Acid

Zoledronic Acid brand names: Zometa, Aclasta, Reclast.

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

Iron has a moderate interaction with Zoledronic Acid. Iron reduces the absorption of bisphosphonates.

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

Iron and Zoledronic Acid

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

Moderate

BISPHOSPHONATES

Why this applies to Zoledronic Acid

Zoledronic Acid falls under BISPHOSPHONATES — the group Iron interacts with.

Iron reduces the absorption of bisphosphonates.
Advise patients that doses of bisphosphonates should be separated by at least two hours from doses of all other medications, including supplements such as iron. Divalent cations, including iron, can decrease absorption of bisphosphonates by forming 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 some good news first: the version of zoledronic acid most people get (Reclast, Zometa, Aclasta) is given as an IV infusion straight into a vein, so an iron pill in your stomach won't affect it. This interaction is really about oral bisphosphonates that you swallow. Iron is a divalent mineral, and it can grab onto a swallowed bisphosphonate in the gut and form a clump your body can't absorb, which means less of the medicine gets in and it works less well for protecting your bones.

This concern is based on how these drugs behave chemically rather than strong human studies. If you ever take an oral bisphosphonate, separating it from iron by a couple of hours is wise. For the IV form, just confirm with your pharmacist that nothing else needs spacing.

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.

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 Zoledronic Acid 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. Zoledronic Acid)
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.

Everything else you take

See Every Supplement That Interacts With Zoledronic Acid

This page covers Iron only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Zoledronic Acid page lists 6 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Calcium (moderate), Dolomite (moderate), Magnesium (moderate), Phosphate Salts (moderate) and Whey Protein (moderate).

By severity: 6 moderate.

From our pharmacist’s overview on the Zoledronic Acid page

“Most people on zoledronic acid (Reclast, Zometa) take it to protect their bones, and many are also told to take calcium, which happens to be the headline item on this short interaction list. All six ingredients on file rate moderate, none major, so these combinations are workable for most people once you realize that timing is nearly t…”

Reviewed by 2 · Jul 18, 2026

Open the Zoledronic Acid 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 Zoledronic Acid 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 Zoledronic Acid 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 Zoledronic Acid
Steady interest

#2,187 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 Zoledronic Acid Injection

What Is Zoledronic Acid Injection Used For?

Brand names: Zometa, Aclasta, Reclast

Zoledronic acid injection is used to treat and prevent osteoporosis in postmenopausal women, increase bone mass in men with osteoporosis, and treat or prevent osteoporosis caused by long-term steroid (glucocorticoid) use in men and women. It is also used to treat Paget's disease of bone in men and women.

In postmenopausal women with osteoporosis, it reduces the risk of hip, spine, and other fractures. For patients at low fracture risk, your doctor may consider stopping therapy after 3 to 5 years — the right duration is a conversation to have with your prescriber.

See full Zoledronic Acid Injection 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 Zoledronic Acid, 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 Zoledronic Acid supplement interactions › Every supplement checked against Zoledronic Acid, ranked by severity Zoledronic Acid Injection 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 Zoledronic Acid Together: Common Questions

Can you take Iron with Zoledronic Acid?
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 Zoledronic Acid 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 Zoledronic Acid 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.