Drug & supplement interaction

Iron + Chlorthalidone

Chlorthalidone brand names: Hygroton, Thalitone.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 20, 2026

The bottom line No known interaction

We found no known interaction between Iron and Chlorthalidone in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Chlorthalidone states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Iron and Chlorthalidone

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Chlorthalidone and Iron in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Iron safety at a glance

Iron overall Use caution Generally safe at recommended doses, but excess iron can be toxic and supplements should be used when there is a real need.

Pregnancy Likely Safe When used orally and appropriately. Iron is safe during pregnancy and breast-feeding in patients with adequate iron stores when used in doses below the tolerabl... Read the full pregnancy detail

Breastfeeding Likely Safe When used orally and appropriately. Iron is safe during pregnancy and breast-feeding in patients with adequate iron stores when used in doses below the tolerabl... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Chlorthalidone and Iron? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Chlorthalidone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Chlorthalidone is filed under 5 classifications — including thiazide diuretics, diuretic drugs, antihypertensive drugs. Iron has documented interactions with 13 drug classes — the most serious being bictegravir/emtricitabine/tenofovir alafenamide (biktarvy) (moderate), bisphosphonates (moderate) and denosumab (prolia, others) (moderate) — and none of Chlorthalidone’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Iron Does Interact With Other Medications

Iron has 79 moderate, 1 minor known drug interactions in our database — Chlorthalidone isn’t one of them. If you take anything else, check it against the full list below.

Moderate 79 Minor 1 No known interaction 2,750 (incl. Chlorthalidone)

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.

What to actually watch for

No Interaction Found — But Data Suggests Iron and Chlorthalidone May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 3 of them are worth acting on rather than waiting out — marked below.

Anemia Worth acting on Additional detail
Iron
“Intravenous (IV) iron may trigger hypophosphatemia in some patients, and cases of osteomalacia related to hypophosphatemia subsequent to parenteral iron administration have been rarely reported. In one case, a 70-year-old male with a genetic hemorrhagic disorder infused with ferric carboxymaltose developed lower limb pain with hypophosphatemia and diffuse bone demineralization in the feet.”

Iron · Natural Medicines adverse-effect record, reported in anemia.
3 sources cited

112609. Samões B, Silva B, Martins A, et al. Hypophosphatemic osteomalacia induced by intravenous iron therapy: a case report. Joint Bone Spine 2023;90(5):105586. PubMed

113905. Ye S, Grill V, Luo J, Nguyen HH. Concurrent Denosumab and Parenteral Iron Therapy Precipitating Severe Hypocalcemia and Hypophosphatemia. JCEM Case Rep 2024;2(2):luae005. PubMed

112603. Kancherla K, Constantin H, Kanawati A, Graham E. Iron-induced Hypophosphatemic Osteomalacia-An Atypical Case of Bilateral Femoral Stress Fractures. J Am Acad Orthop Surg Glob Res Rev 2023;7(5):e22. PubMed
“Although there is some clinical research associating iron supplementation with an increased rate of malaria infection, the strongest evidence to date does not support this association, at least for areas where antimalarial treatment is available. In an analysis of 14 trials, iron supplementation was not associated with an increased risk of malaria.”

Iron · Natural Medicines adverse-effect record, reported in anemia.
6 sources cited

56796. van den, Hombergh J., Dalderop, E., and Smit, Y. Does iron therapy benefit children with severe malaria-associated anaemia? A clinical trial with 12 weeks supplementation of oral iron in young children from the Turiani Division, Tanzania. J.Trop.Pediatr. PubMed

95432. Esan MO, Boele van Hensbroek M, Nkhoma E, et al. Iron supplementation in HIV infected Malawian children with anemia: a double-blind, randomized, controlled trial. Clin Inf Dis 2013;57(11):1626-34.doi:10.1093/cid/cit528. PubMed

95433. Zlotkin S, Newton S, Aimone AM, et al. Effect of iron fortification on malaria incidence in infants and young children in Ghana: a randomized trial. JAMA 2013;310(9):938-47. PubMed

96623. Neuberger A, Okebe J, Yahav D, Paul M. Oral iron supplements for children in malaria-endemic areas. Cochrane Database Syst Rev. 2016;2:CD006589. PubMed

110186. Shah AA, Donovan K, Seeley C, et al. Risk of infection associated with administration of intravenous iron: A systematic review and meta-analysis. JAMA Netw Open 2021;4(11):e2133935. PubMed

115892. Meyers M, Salmon M, Libert I, Klá&scaron;terský J. A meta-analysis on the risk of infection associated with intravenous iron therapy in cancer-associated anaemia: a double-edged sword?. Curr Opin Oncol 2024;36(4):223-232. PubMed
Chlorthalidone

Listed in the ADVERSE REACTIONS section of the FDA label for Chlorthalidone. Read the label on DailyMed ›
Bleeding or bruising Worth acting on Additional detail
Iron
“Orally, iron can cause dry mouth, gastrointestinal irritation, heartburn, abdominal pain, constipation, diarrhea, nausea, or vomiting. These adverse effects are uncommon at doses below the tolerable upper intake level (UL) of 45 mg per day of elemental iron in adults with normal iron stores. Higher doses can be taken safely in adults with iron deficiency, but gastrointestinal side effects may occur.”

Iron · Natural Medicines adverse-effect record, reported in alzheimer disease.
6 sources cited

96621. Low MS, Speedy J, Styles CE, De-Regil LM, Pasricha SR. Daily iron supplementation for improving anaemia, iron status and health in menstruating women. Cochrane Database Syst Rev. 2016;4:CD009747. PubMed

102864. Kaundal R, Bhatia P, Jain A, et al. Randomized controlled trial of twice-daily versus alternate-day oral iron therapy in the treatment of iron-deficiency anemia. Ann Hematol 2020;99(1):57-63. PubMed

104680. Li N, Zhao G, Wu W, et al. The efficacy and safety of vitamin C for iron supplementation in adult patients with iron deficiency anemia: A randomized clinical trial. JAMA Netw Open. 2020;3(11):e2023644.<br> PubMed

104684. Houston BL, Hurrie D, Graham J, et al. Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials. BMJ Open. 2018;8(4):e019240. PubMed

110179. Koch RM, Tchernodrinski S, Principe DR. Case report: Rapid onset, ischemic-type gastritis after initiating oral iron supplementation. Front Med (Lausanne) 2022;9:1010897. PubMed

110185. Rogozinska E, Daru J, Nicolaides M, et al. Iron preparations for women of reproductive age with iron deficiency anaemia in pregnancy (FRIDA): a systematic review and network meta-analysis. Lancet Haematol 2021;8(7):e503-e512. PubMed
“Orally, iron has been associated with rare reports of iron pill aspiration. This occurs when all or part of the pill is aspirated into the lungs. Once in the lungs, it can cause a chemical burn of the bronchial mucosa. Dozens of cases of iron pill aspiration have been reported in individuals ranging in age from 22 months to 92 years. Patients presented with cough, dyspnea, wheezing, and hemoptysis.”

Iron · Natural Medicines adverse-effect record, reported in burns.

Chlorthalidone

Listed in the ADVERSE REACTIONS section of the FDA label for Chlorthalidone. Read the label on DailyMed ›
An allergic reaction Worth acting on Additional detail

Iron

Recorded for Iron in the same Natural Medicines adverse-effect record shown under Anemia above.

Chlorthalidone

Listed in the ADVERSE REACTIONS section of the FDA label for Chlorthalidone. Read the label on DailyMed ›
Low blood pressure / A skin rash Additional detail
Iron
“Intravenously, sodium ferric gluconate complex (SFGC) caused drug intolerance reactions in 0.4% of hemodialysis patients including 2 patients with pruritus and one patient each with anaphylactoid reaction, hypotension, chills, back pain, dyspnea/chest pain, facial flushing, rash and cutaneous symptoms of porphyria.”

Iron · Natural Medicines adverse-effect record, reported in back pain.
1 source cited

56527. Michael, B., Coyne, D. W., Fishbane, S., Folkert, V., Lynn, R., Nissenson, A. R., Agarwal, R., Eschbach, J. W., Fadem, S. Z., Trout, J. R., Strobos, J., and Warnock, D. G. Sodium ferric gluconate complex in hemodialysis patients: adverse reactions compar
Chlorthalidone

Listed in the ADVERSE REACTIONS section of the FDA label for Chlorthalidone. Read the label on DailyMed ›
Stomach upset Additional detail

Iron

Recorded for Iron in the same Natural Medicines adverse-effect record shown under Bleeding or bruising above.

Chlorthalidone

Listed in the ADVERSE REACTIONS section of the FDA label for Chlorthalidone. Read the label on DailyMed ›
Constipation / Diarrhea / Vomiting Additional detail

Iron

“Orally or intravenously, iron is generally well tolerated when used appropriately.

Most Common Adverse Effects:

Orally: Abdominal pain, constipation, diarrhea, gastrointestinal irritation, nausea, and vomiting.

Serious Adverse Effects (Rare):

Orally: Case reports have raised concerns about oral or gastric ulcerations.

Intravenously: Case reports have raised concerns about hypophosphatemia and osteomalacia.”

Iron · Natural Medicines adverse-effect record, reported in constipation.

Chlorthalidone

Listed in the ADVERSE REACTIONS section of the FDA label for Chlorthalidone. Read the label on DailyMed ›
Headache Additional detail
Iron
“There is debate regarding the association between coronary heart disease (CHD) or myocardial infarction (MI) and high iron intake or high body iron stores. Some observational studies have reported that high body iron stores are associated with increased risk of MI and CHD.”

Iron · Natural Medicines adverse-effect record, reported in alcohol-related liver disease.
6 sources cited

1492. Klipstein-Grobusch K, Grobbee DE, den Breeijen JH, et al. Dietary iron and risk of myocardial infarction in the Rotterdam Study. Am J Epidemiol 1999;149:421-8. PubMed

9542. Schumann K, Borch-Iohnsen B, Hentze MW, Marx JJ. Tolerable upper intakes for dietary iron set by the US Food and Nutrition Board (commentary). Am J Clin Nutr 2002;76:499-500. PubMed

9544. Tuomainen TP, Punnonen K, Nyyssonen K, Salonen JT. Association between body iron stores and the risk of acute myocardial infarction in men. Circulation 1998;97:1461-6.. PubMed

9545. Salonen JT, Nyyssonen K, Korpela H, et al. High stored iron levels are associated with excess risk of myocardial infarction in Eastern Finnish men. Circulation 1992;86:803-11.. PubMed

15175. Kiechl S, Willeit J, Egger G, et al. Body iron stores and the risk of carotid atherosclerosis: prospective results from the Bruneck study. Circulation 1997;96:3300-07. PubMed

112607. Jara Vidal M, López García MC, Quílez Toboso RP. Kounis syndrome after intravenous iron administration. Med Clin (Barc) 2023. DOI
Chlorthalidone

Listed in the ADVERSE REACTIONS section of the FDA label for Chlorthalidone. Read the label on DailyMed ›

Showing the 10 most notable of 11 shared effects — ranked by how unusual each one is, not just whether both lists mention it.

Reported for Iron but not commonly for Chlorthalidone: kidney problems, a severe allergic reaction, a heart attack and sweating.

Effects for Chlorthalidone come from the ADVERSE REACTIONS section of its FDA label; effects for Iron come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Iron in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally and appropriately. Iron is safe during pregnancy and breast-feeding in patients with adequate iron stores when used in doses below the tolerable upper intake level (UL) of 45 mg daily of elemental iron.

Pregnancy And Lactation Likely Unsafe

When used orally in high doses. Tell patients who are not iron deficient to avoid exceeding the tolerable upper intake level (UL) of 45 mg daily of elemental iron. Higher doses frequently cause gastrointestinal side effects such as nausea and vomiting and might increase the risk of preterm labor. High hemoglobin concentrations at the time of delivery are associated with adverse pregnancy outcomes.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

Some Chlorthalidone Products Have a Food Rule — Iron Should Not Break It

At least one FDA label for a product containing Chlorthalidone says to take it with food. If you take Iron on an empty stomach out of habit, keep them separate — and take Chlorthalidone with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Chlorthalidone products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Hypertension The initial recommended dose is 15 mg once daily with food.

From the Dosage and Administration section of the FDA label we read for Chlorthalidone — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Chlorthalidone Is Prescribed For, and What Iron Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Chlorthalidone is a prescription medicine with approved uses on its FDA label. Iron is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Chlorthalidone is prescribed for: Chlorthalidone is used to treat high blood pressure (hypertension) in adults. Lowering blood pressure reduces the risk of serious cardiovascular events, especially strokes and heart attacks. It can be used alone or combined with other blood pressure medicines. Chlorthalidone is also used as an add-on treatment for edema (fluid buildup) caused by heart failure, liver cirrhosis, and kidney conditions including nephrotic syndrome, acute glomerulonephritis, and chronic renal failure.

Read the rest of what Chlorthalidone is prescribed for

Thalitone is additionally indicated for edema associated with heart failure, liver cirrhosis, and renal disease including nephrotic syndrome.

Iron has been studied for:

Heart failure Natural Medicines rates the evidence for Iron: Possibly Effective Read what the research shows

Iron for heart failure

Intravenous (IV) iron seems to be effective for improving certain outcomes in patients with heart failure and iron deficiency. It is unclear if oral iron is effective.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Chlorthalidone on your own; if you are taking Iron for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Iron or Chlorthalidone

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 Chlorthalidone, 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 Chlorthalidone

This page covers Iron only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chlorthalidone page lists 222 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Dolomite (major) and Lithium (major).

By severity: 8 major · 190 moderate · 24 minor.

From our pharmacist’s overview on the Chlorthalidone page

“Chlorthalidone (Hygroton, Thalitone) lowers blood pressure by helping the kidneys shed salt and water, and that mechanism makes its supplement interactions worth genuine care. Most of the 222 ingredients on file either add to its blood-pressure-lowering effect or act as diuretics themselves, so pressure or potassium can fall further th…”

Reviewed by 2 · Jul 18, 2026

Open the Chlorthalidone 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. Even though Iron itself has no known interaction with Chlorthalidone, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Iron and Chlorthalidone 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 5%

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

29 days ago today

Medication Chlorthalidone

Steady interest

#1,449 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.

Where does our data come from?

Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Iron reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Iron and Chlorthalidone records this page draws on were last updated July 10, 2026.
What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.

Data structure & sourcing designed and verified by Dr. Brian Staiger, PharmD, BCPS.

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.

Mineral (essential trace element) · Tablets, capsules, liquid/drops, gummies, chewables, and intravenous (IV) preparations

An interaction check asks whether these two react with each other — it does not ask whether Iron is a good idea for someone in your situation. Here is what our Iron record says about it on its own.

Iron: dosing

Treatment doses for anemia are usually higher than amounts found in a daily multivitamin.Follow the dose on your product label or the dose your healthcare provider gives you.

From our Iron monograph — the full record covers uses, side effects and every documented interaction.

Read the full Iron monograph & all interactions

Medication

About Chlorthalidone

What Is Chlorthalidone Used For?

Brand names: Hygroton, Thalitone

Chlorthalidone is used to treat high blood pressure (hypertension) in adults. Lowering blood pressure reduces the risk of serious cardiovascular events, especially strokes and heart attacks. It can be used alone or combined with other blood pressure medicines.

Chlorthalidone is also used as an add-on treatment for edema (fluid buildup) caused by heart failure, liver cirrhosis, and kidney conditions including nephrotic syndrome, acute glomerulonephritis, and chronic renal failure. Thalitone is additionally indicated for edema associated with heart failure, liver cirrhosis, and renal disease including nephrotic syndrome.

Most-Reported Side Effects for Chlorthalidone

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Nausea 1,258 reports

Fatigue 1,063 reports

Diarrhea 849 reports

Dizziness 758 reports

Headache 715 reports

See full Chlorthalidone 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

79Moderate

1Minor

2,749No known interaction

79 Moderate 1 Minor 2,749 No interaction

Moderate

79 interactions

Showing 60 of 79 moderate interactions — see all 79 on the Iron page.

Minor

1 interaction

Chloramphenicol ›

No interaction 2,749 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 2,749 medications checked with no known interaction — see the full Iron list.

See the full Iron interactions page

See every supplement checked against Chlorthalidone, ranked by severity

Evidence & sources

Iron References

The 72 references that drive our Iron monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
Bruner AB, Joffe A, Duggan AK, et al. Randomized study of cognitive effects of iron supplementation in non- anaemic iron-deficient adolescent girls. Lancet 1996;348:992-6.
Ullen H, Augustsson K, Gustavsson C, Steineck G. Supplementary iron intake and risk of cancer: reversed causality? Cancer Lett 1997;114:215-6.
Reunanen A, Takkunen H, Knekt P, et al. Body iron stores, dietary iron intake and coronary heart disease mortality. J Intern Med 1995;238:223-30. PubMed
Lund EK, Wharf SG, Fairweather-Tait SJ, Johnson IT. Oral ferrous sulfate supplements increase the free radical-generating capacity of feces from healthy volunteers. Am J Clin Nutr 1999;69:250-5.
Rehman A, Collis CS, Yang M, et al. The effects of iron and vitamin C co-supplementation on oxidative damage to DNA in healthy volunteers. Biochem Biophys Res Comm 1998;246:293-8. PubMed
Klipstein-Grobusch K, Grobbee DE, den Breeijen JH, et al. Dietary iron and risk of myocardial infarction in the Rotterdam Study. Am J Epidemiol 1999;149:421-8. PubMed
Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
Tatro DS, ed. Drug Interactions Facts. Facts and Comparisons Inc., St. Louis, MO. 1999.
Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
Campbell N, Paddock V, Sundaram R. Alteration of methyldopa absorption, metabolism, and blood pressure control by ferrous sulfate and ferrous gluconate. Clin Pharmacol Ther 1988;43:381-6..
Schumann K, Borch-Iohnsen B, Hentze MW, Marx JJ. Tolerable upper intakes for dietary iron set by the US Food and Nutrition Board (commentary). Am J Clin Nutr 2002;76:499-500. PubMed
Tuomainen TP, Punnonen K, Nyyssonen K, Salonen JT. Association between body iron stores and the risk of acute myocardial infarction in men. Circulation 1998;97:1461-6.. PubMed
Salonen JT, Nyyssonen K, Korpela H, et al. High stored iron levels are associated with excess risk of myocardial infarction in Eastern Finnish men. Circulation 1992;86:803-11.. PubMed
Campbell NRC, Hasinoff B. Ferrous sulfate reduces levodopa bioavailability: Chelation as a possible mechanism. Clin Pharmacol Ther 1989;45:220-5.. PubMed
Campbell NRC, Hasinoff BB, Stalts H, et al. Ferrous sulfate reduces thyroxine efficacy in patients with hypothyroidism. Ann Int Med 1992;117:1010-3.. PubMed
Kiechl S, Willeit J, Egger G, et al. Body iron stores and the risk of carotid atherosclerosis: prospective results from the Bruneck study. Circulation 1997;96:3300-07. PubMed
Comparison of oral iron supplements. Pharmacist's Letter / Prescriber's Letter 2008;24(8):240811.
Tran T., Wax J. R., Philput C., Steinfeld J. D., Ingardia C. J. Intentional iron overdose in pregnancy--management and outcome. J Emerg Med 2000;18(2):225-228. PubMed
Toblli J. E., Brignoli, R. Iron(III)-hydroxide polymaltose complex in iron deficiency anemia / review and meta-analysis. Arzneimittelforschung 2007;57(6A):431-438. PubMed
Köpcke W., Sauerland M. C. Meta-analysis of efficacy and tolerability data on iron proteinsuccinylate in patients with iron deficiency anemia of different severity. Arzneimittelforschung 1995;45(11):1211-1216.
Campbell N. R., Campbell R. R., Hasinoff B. B. Ferrous sulfate reduces methyldopa absorption: methyldopa: iron complex formation as a likely mechanism. Clin Invest Med 1990;13(6):329-332.
Morii M., Ueno K., Ogawa A., Kato R., Yoshimura H., Wada K., Hashimoto H., Takada M., Tanaka K., Nakatani T., Shibakawa M. Impairment of mycophenolate mofetil absorption by iron ion. Clin Pharmacol Ther 2000;68(6):613-616. PubMed
Gelone D. K., Park J. M., Lake K. D. Lack of an effect of oral iron administration on mycophenolic acid pharmacokinetics in stable renal transplant recipients. Pharmacotherapy 2007;27(9):1272-1278. PubMed
Ducray P. S., Banken L., Gerber M., Boutouyrie B., Zandt H. Absence of an interaction between iron and mycophenolate mofetil absorption. Br J Clin Pharmacol 2006;62(4):492-495. PubMed
Lorenz M., Wolzt M., Weigel G., Puttinger H., Hörl W. H., Födinger M., Speiser W., Sunder-Plassmann G. Ferrous sulfate does not affect mycophenolic acid pharmacokinetics in kidney transplant patients. Am J Kidney Dis 2004;43(6):1098-1103. PubMed
Osman M. A., Patel R. B., Schuna A., Sundstrom W. R., Welling P. G. Reduction in oral penicillamine absorption by food, antacid, and ferrous sulfate. Clin Pharmacol Ther 1983;33(4):465-470. PubMed
Michael, B., Coyne, D. W., Fishbane, S., Folkert, V., Lynn, R., Nissenson, A. R., Agarwal, R., Eschbach, J. W., Fadem, S. Z., Trout, J. R., Strobos, J., and Warnock, D. G. Sodium ferric gluconate complex in hemodialysis patients: adverse reactions compar
Zhang, X., Ouyang, J., Wieczorek, R., and DeSoto, F. Iron medication-induced gastric mucosal injury. Pathol.Res Pract 2009;205(8):579-581. PubMed
Barbieri, P. G. [To-day exposure to occupational carcinogens and their effects. The experience of the rubber industry, iron metallurgy, asphalt work and aviculture]. Epidemiol.Prev 2009;33(4-5 Suppl 2):94-105.
Macedo, A. and Cardoso, S. [Routine iron supplementation in pregnancy]. Acta Med Port. 2010;23(5):785-792.
Bastide, N. M., Pierre, F. H., and Corpet, D. E. Heme iron from meat and risk of colorectal cancer: a meta-analysis and a review of the mechanisms involved. Cancer Prev Res (Phila) 2011;4(2):177-184. PubMed
Stevens, R. G. Iron and the risk of cancer. Med Oncol Tumor Pharmacother. 1990;7(2-3):177-181. PubMed
van den, Hombergh J., Dalderop, E., and Smit, Y. Does iron therapy benefit children with severe malaria-associated anaemia? A clinical trial with 12 weeks supplementation of oral iron in young children from the Turiani Division, Tanzania. J.Trop.Pediatr. PubMed
Liabeuf S, Gras V, Moragny J, et al. Ulceration of the oral mucosa following direct contact with ferrous sulfate in elderly patients: a case report and a review of the French National Pharmacovigilance Database. Clin Interv Aging. 2014 Apr 25;9:737-40. PubMed
Qiao L, Feng Y. Intakes of heme iron and zinc and colorectal cancer incidence: a meta-analysis of prospective studies. Cancer Causes Control. 2013 Jun;24(6):1175-83. PubMed
Jalloh MA, Gregory PJ, Hein D, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15. PubMed
Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents: Drug Interactions between Integrase Inhibitors and Other Drugs. AIDSinfo. July 14, 2016. Available at: https://aidsinfo.nih.gov/guidelines/html/1/adult-and-adolescen
Song I, Borland J, Arya N, Wynne B, Piscitelli S. Pharmacokinetics of dolutegravir when administered with mineral supplements in healthy adult subjects. J Clin Pharmacol. 2015;55(5):490-6. PubMed
Esan MO, Boele van Hensbroek M, Nkhoma E, et al. Iron supplementation in HIV infected Malawian children with anemia: a double-blind, randomized, controlled trial. Clin Inf Dis 2013;57(11):1626-34.doi:10.1093/cid/cit528. PubMed
Zlotkin S, Newton S, Aimone AM, et al. Effect of iron fortification on malaria incidence in infants and young children in Ghana: a randomized trial. JAMA 2013;310(9):938-47. PubMed
Khambalia AZ, Aimone A, Nagubandi P, et al. High maternal iron status, dietary iron intake and iron supplement use in pregnancy and risk of gestational diabetes mellitus: a prospective study and systematic review. Diabet Med. 2016;33(9):1211-21. PubMed
Kinnunen TI, Luoto R, Helin A, Hemminki E. Supplemental iron intake and the risk of glucose intolerance in pregnancy: re-analysis of a randomised controlled trial in Finland. Matern Child Nutr. 2016;12(1):74-84.
Low MS, Speedy J, Styles CE, De-Regil LM, Pasricha SR. Daily iron supplementation for improving anaemia, iron status and health in menstruating women. Cochrane Database Syst Rev. 2016;4:CD009747. PubMed
Melit LE, Marginean CO, Mocanu S, Marginean MO. A rare case of iron-pill induced gastritis in a female teenager: A case report and a review of the literature. Medicine (Baltimore). 2017;96(30):e7550. PubMed
Neuberger A, Okebe J, Yahav D, Paul M. Oral iron supplements for children in malaria-endemic areas. Cochrane Database Syst Rev. 2016;2:CD006589. PubMed
Peña-Rosas JP, De-Regil LM, Gomez Malave H, Flores-Urrutia MC, Dowswell T. Intermittent oral iron supplementation during pregnancy. Cochrane Database Syst Rev. 2015;(10):CD009997. PubMed
Brabin B, Gies S, Roberts SA, et al. Excess risk of preterm birth with periconceptional iron supplementation in a malaria endemic area: analysis of secondary data on birth outcomes in a double blind randomized controlled safety trial in Burkina Faso. Mala PubMed
Kaundal R, Bhatia P, Jain A, et al. Randomized controlled trial of twice-daily versus alternate-day oral iron therapy in the treatment of iron-deficiency anemia. Ann Hematol 2020;99(1):57-63. PubMed
Li N, Zhao G, Wu W, et al. The efficacy and safety of vitamin C for iron supplementation in adult patients with iron deficiency anemia: A randomized clinical trial. JAMA Netw Open. 2020;3(11):e2023644.<br> PubMed
Houston BL, Hurrie D, Graham J, et al. Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials. BMJ Open. 2018;8(4):e019240. PubMed
Koch RM, Tchernodrinski S, Principe DR. Case report: Rapid onset, ischemic-type gastritis after initiating oral iron supplementation. Front Med (Lausanne) 2022;9:1010897. PubMed
Milman NT. Iron supplementation in pregnant Danish women revisited: Effects on prepartum and postpartum iron deficiency, anemia, serum erythropoietin; including iron status, erythropoietin and anthropometrics in newborns. A randomized, placebo-controlled
Rogozinska E, Daru J, Nicolaides M, et al. Iron preparations for women of reproductive age with iron deficiency anaemia in pregnancy (FRIDA): a systematic review and network meta-analysis. Lancet Haematol 2021;8(7):e503-e512. PubMed
Shah AA, Donovan K, Seeley C, et al. Risk of infection associated with administration of intravenous iron: A systematic review and meta-analysis. JAMA Netw Open 2021;4(11):e2133935. PubMed
Gamad N, Saha PK, Sharma P, Suri V, Chakrabarti A, Saha L. A randomized controlled trial comparing the efficacy, tolerability, and cost of oral iron preparations in iron-deficiency anemia in pregnancy. J Obstet Gynaecol Res 2021;47(11):3828-3841. PubMed
El-Hawy MA, Abd Al-Salam SA, Bahbah WA. Comparing oral iron bisglycinate chelate, lactoferrin, lactoferrin with iron and iron polymaltose complex in the treatment of children with iron deficiency anemia. Clin Nutr ESPEN 2021;46:367-371. PubMed
Adams A, Scheckel B, Habsaoui A, et al. Intravenous iron versus oral iron versus no iron with or without erythropoiesis- stimulating agents (ESA) for cancer patients with anaemia: a systematic review and network meta-analysis. Cochrane Database Syst Rev 2 PubMed
Kancherla K, Constantin H, Kanawati A, Graham E. Iron-induced Hypophosphatemic Osteomalacia-An Atypical Case of Bilateral Femoral Stress Fractures. J Am Acad Orthop Surg Glob Res Rev 2023;7(5):e22. PubMed
Shi R, Marin JG, Beaulieu M. Skin staining following intravenous iron extravasation in a patient with chronic kidney disease: A case report. Can J Kidney Health Dis 2023;10:20543581231165705. PubMed
Varandas C, Vieira J, Correia CJ, et al. Hypersensitivity reactions to iron products: 10-year experience in a Portuguese tertiary Centre. Eur Ann Allergy Clin Immunol 2023.
Jara Vidal M, López García MC, Quílez Toboso RP. Kounis syndrome after intravenous iron administration. Med Clin (Barc) 2023. DOI
Jara Vidal M, Ruiz de Assín Valverde A, Aznar Rodríguez S. Severe hypophospathemia secondary to intravenous iron. Med Clin (Barc) 2023. DOI
Samões B, Silva B, Martins A, et al. Hypophosphatemic osteomalacia induced by intravenous iron therapy: a case report. Joint Bone Spine 2023;90(5):105586. PubMed
Seng NW, Barco JB, Wong MH, et al. Hypophosphatemia related to intravenous iron therapy with ferric carboxymaltose: A case series. Transfus Med 2023. PubMed
Fernandez-Flores A, Fernandez-Parrado M, Alzoghby-Abi Chaker J, Angulo AG. Axillary cutaneous hemosiderosis in a patient with hyperhidrosis, after intravenous iron infusion. Am J Dermatopathol 2023;45(7):463-465. PubMed
Ye S, Grill V, Luo J, Nguyen HH. Concurrent Denosumab and Parenteral Iron Therapy Precipitating Severe Hypocalcemia and Hypophosphatemia. JCEM Case Rep 2024;2(2):luae005. PubMed
Yerigeri K. Hemochromatosis in an Adult Female With Previous Iron Deficiency Anemia on Iron Supplementation. Cureus 2023;15(12):e50166. PubMed
Meyers M, Salmon M, Libert I, Klá&scaron;terský J. A meta-analysis on the risk of infection associated with intravenous iron therapy in cancer-associated anaemia: a double-edged sword?. Curr Opin Oncol 2024;36(4):223-232. PubMed
Short V, Allen R, Earley CJ, et al. A randomized double-blind pilot study to evaluate the efficacy, safety, and tolerability of intravenous iron versus oral iron for the treatment of restless legs syndrome in patients with iron deficiency anemia. Am J Hem PubMed
Bellos I, Frountzas M, Pergialiotis V. Comparative Risk of Hypophosphatemia Following the Administration of Intravenous Iron Formulations: A Network Meta-Analysis. Transfus Med Rev 2020;34(3):188-194. PubMed
US Food and Drug Administration (FDA). Biktarvy Prescribing Information. October 2024. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/210251Orig1s020lbl.pdf. Accessed July 16, 2025.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Related: nutrient depletion

Chlorthalidone Is Linked to Lower Levels of 8 Nutrients

Natural Medicines records Chlorthalidone as a medicine that can lower these. This is not an interaction with Iron — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:

Read the full Chlorthalidone nutrient depletion report ›

Iron is itself a nutrient we track — see which medications may deplete IRON.

Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.

Pharmacist Counseling Corner

Taking Iron and Chlorthalidone Together: Common Questions

Is it safe to take Iron with Chlorthalidone?

We do not list a known interaction between Iron and Chlorthalidone. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

Do Iron and Chlorthalidone have any of the same side effects?

Yes — our sources link each of them separately to 10 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.

Should I take Iron and Chlorthalidone at the same time of day?

At least one FDA label for a product containing Chlorthalidone says to take it with food. If you take Iron on an empty stomach out of habit, keep them separate and take Chlorthalidone with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Chlorthalidone products can differ — so check the directions on your own box. This is about absorption, not an interaction.

Are Iron and Chlorthalidone used for the same thing?

They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Iron in each. That is a conversation for your prescriber, especially if Chlorthalidone is being adjusted to a target.

How was the Iron and Chlorthalidone combination checked?

Interactions in our licensed database are recorded against drug classes. Chlorthalidone is filed under 5 classifications, and Iron has documented interactions with 13 drug classes — none of Chlorthalidone's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.

Does Iron interact with any other medications?

Yes. Iron has 80 documented drug interactions in our database — Chlorthalidone is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Does Chlorthalidone interact with any supplements?

Yes. Chlorthalidone has documented interactions with 222 supplements in our database — Iron is not one of them. The Chlorthalidone interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Iron monograph Uses, safety profile, and every drug interaction in one place Chlorthalidone drug information The full plain-English guide to this medication Chlorthalidone supplement interactions Every supplement checked against Chlorthalidone, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 72 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Chlorthalidone and Iron?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.

abdominal pain: Pain, cramping, or discomfort felt anywhere in the belly area.

Absorption: How a medicine moves from where it is taken, such as the stomach or gut, into the bloodstream.

anaphylactoid reaction: A severe reaction that looks like a serious allergic reaction but is not caused by the usual allergy antibodies.

constipation: Having bowel movements less often than usual, or passing stools that are hard, dry, and difficult to move.

diarrhea: Loose, watery bowel movements that happen more often than normal.

Drug Interactions: The label section listing other medicines, foods, or substances that can change how a medicine works or raise the chance of side effects.

dyspnea: The medical word for shortness of breath, or the feeling that you cannot get enough air.

flushing: Temporary redness and warmth of the skin, often on the face and neck, from widening of small blood vessels.

hemodialysis: A treatment that uses a machine to filter waste and extra fluid from the blood when the kidneys cannot.

hemoptysis: Coughing up blood or bloody mucus from the lungs or airways.

hypophosphatemia: A lower-than-normal level of phosphate, a mineral, in the blood.

hypotension: Blood pressure that is lower than normal, which can cause dizziness or fainting.

intravenous: Given directly into a vein through a needle or thin tube; often written as IV.

myocardial infarction: The medical term for a heart attack, when blood flow to part of the heart muscle is blocked.

osteomalacia: Softening of the bones, often from low vitamin D, that can cause bone pain and weakness.

parenteral: Given by injection or drip into the body rather than swallowed by mouth.

pruritus: Itching of the skin.

wheezing: A high-pitched whistling sound made while breathing, usually when the airways are narrowed.