Iron Isomaltoside 1000.
Research-backed mineral with potential health benefits. Rapidly replenishes your body's iron stores and hemoglobin.
Reviewed March 2026
- Category
- Mineral
What Iron Isomaltoside 1000 is, and what it does.
- Does it work
- Yes. For a 'little boost'? Absolutely not. Get tested first.
- How much to take
- It's a one-time dose, usually 1000-1500mg, prescribed by your doctor and given as an IV infusion over about 30-60 minutes.
- Time to feel it
- Red cell production picks up within days, haemoglobin climbs over the following month, and ferritin stays topped up for months afterwards.
- The first dose
- Nothing significant. Maybe a mild headache or feeling a bit off post-infusion. The real magic happens over the next few weeks as your body builds new red blood cells.
- With regular use
- Energy, stamina, and cognitive function return to normal. Your ferritin levels stay topped up for many months, even over a year.
- How well tolerated
- Well tolerated when administered by a healthcare professional. They monitor for rare allergic reactions. Bypasses the gut, so zero constipation or stomach upset.
- How it feels
- The result feels like getting your life back. The process feels like sitting in a comfy chair with an IV in your arm for an hour.
- The overlooked benefit
- The short, straight carbohydrate chain holds the iron tightly enough that a large amount can go in during one visit rather than across several appointments.
18 to 27mg a day is where Iron Isomaltoside 1000 works.
Source: NIH ODS + WHO guidelines
The proof, claim by claim.
These words describe the research, not the molecule's worth. Research strength is how much work stands behind one claim, and it is never a product score.
Iron Isomaltoside 1000 is documented in the library; the clinical read is in the queue. Nothing about the strength of the research prints until the read is done.
- haemoglobin response after a single high-dose infusionRandomised trial
- ferritin repletion sustained over several monthsRandomised trial
- effect on blood phosphate compared with other intravenous iron complexesRandomised trial
- iron delivery when the intestinal route is bypassedNarrative review
Questions people ask about Iron Isomaltoside 1000.
- Is this a pill I can buy?
- No. It's a prescription-only intravenous (IV) infusion you get at a doctor's office or infusion center.
- Is it better than iron pills?
- For people who can't tolerate or absorb pills, yes. It's a single infusion versus months of daily pills that often cause constipation.
- How fast does it work?
- Your body starts making new red blood cells immediately. Most people start feeling a real difference in their energy levels in 2-4 weeks.
- Will it make me constipated?
- Nope. It completely bypasses your digestive system. That's one of its biggest advantages over oral iron.
- Can I take this just for low energy?
- No. Get your blood tested first. This is a powerful treatment for confirmed iron deficiency, not a casual energy booster.
- What are the side effects?
- Usually minimal. Some people get a headache or feel a little nauseous. There's a small risk of an allergic reaction during the infusion, which is why a nurse monitors you.
Why these belong in the same formula. Each row says what the basis is, from settled biochemistry through to a trial that measured the pair.
Copper-dependent ferroxidase activity is what loads iron onto transferrin after it is released from macrophage stores. This step is required no matter how the iron entered the body.
Once iron is available, marrow precursors still need folate for the DNA synthesis that lets them divide. Output tracks whichever of the two is scarcer.
B12 supports the same nucleotide synthesis step as folate in dividing red cell precursors. Iron supplies the heme those cells load.
Flavins made from riboflavin support the reduction step that releases stored iron for transport. Riboflavin status affects how efficiently delivered iron is used.
Vitamin A status influences release of iron from ferritin stores into circulation. It acts after delivery, so it applies to a carbohydrate-complexed iron as well.
Ascorbate is the classic reducing agent in iron chemistry, converting ferric iron to the ferrous form and helping release iron held in ferritin. That matters for oral non-heme iron, where solubility is the limiting step. For a parenteral carbohydrate complex the absorption step is bypassed entirely, so the relevance is to iron handling after delivery rather than to uptake, and free reducing agents alongside labile iron also drive Fenton chemistry.
Iron cannot be built into heme unless the porphyrin ring is made first, and the opening step of that pathway condenses glycine with succinyl-CoA using pyridoxal 5-phosphate. Delivering iron to a body short of B6 leaves the ring-building step limited. This is settled biochemistry and needs no combination trial.
Every porphyrin ring that later incorporates iron begins with glycine joined to succinyl-CoA. The amino acid is rarely limiting on an ordinary diet, which is why this is a pathway relationship rather than a supplementation recommendation. It explains where iron ends up rather than promising an added effect.
Oral iron and oral zinc compete for the same divalent metal transporter, which is why large oral iron doses lower zinc uptake taken together. A parenteral iron complex does not pass through that transporter, so the competition does not apply to the infusion itself. It applies to any oral iron a person is also taking, and that distinction is the useful one.
Calcium interferes with non-heme iron uptake at the enterocyte when the two arrive together, which is standard dosing advice for oral iron. An intravenous carbohydrate-iron complex sidesteps the intestine and is unaffected. The row exists so the oral rule is not mistakenly carried over to the parenteral form.
Parenteral iron bypasses the hepcidin-controlled intestinal gate that normally limits how much iron the body takes in, so the usual self-limiting mechanism is not available. Continuing oral iron on top of that adds a second source without a corresponding brake, and iron overload from parenteral dosing has been described in single-patient reports. Whether oral iron continues alongside is a prescriber decision.
Lactoferrin binds ferric iron tightly and has been studied as an oral alternative and adjunct in low iron status. Its iron-binding chemistry is established; a measured interaction with a parenteral iron-carbohydrate complex is not something to point at. The pairing is mechanistically coherent and clinically unmeasured.
Free or loosely bound iron catalyses hydroxyl radical formation and lipid peroxidation, which is precisely why parenteral iron is delivered inside a carbohydrate matrix that limits free iron release. Tocopherol terminates lipid radical chains in the membrane phase. The chemistry connects the two; a joint clinical measurement does not exist here.
Nothing specific on file for Iron Isomaltoside 1000. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.What Iron Isomaltoside 1000 actually does.
Iron isomaltoside 1000, also named ferric derisomaltose, is a colloidal complex of an iron(III)-hydroxide core enclosed by linear isomaltoside oligosaccharide, an unbranched carbohydrate of about 1000 daltons.
The carbohydrate shell holds the iron in a matrix structure and limits release of free reactive iron into plasma, which is what allows a large amount of iron to be delivered in one parenteral dose.
Parenteral iron complexes are taken up by macrophages of the reticuloendothelial system, where the carbohydrate is degraded and the iron is transferred to transferrin and to ferritin stores.
A parenteral route bypasses the hepcidin-regulated ferroportin gate in the intestine, so the body's normal mechanism for limiting iron entry does not apply to an infused dose.
Where Iron Isomaltoside 1000 comes from.
It is made in a pharmaceutical plant in two halves. Bacteria fed sugar make a carbohydrate that is cut down to a short, straight chain, and that chain is then wrapped around a core of iron built in a reaction vessel. The wrapping is the point: it keeps the iron from floating free in the bloodstream. The finished liquid is sterile-filled into vials for a clinician to infuse.
The same molecule is reached more than one way. Which route a given product used is a manufacturing choice, and the finished compound is the same either way.
Leuconostoc mesenteroides grown on sucrose produces dextran, a glucose polymer, which is the starting carbohydrate.
Dextran is hydrolysed down to short alpha-1,6-linked oligosaccharides of around 1000 daltons and the reducing end is hydrogenated, giving a linear, non-reducing isomaltoside without branched antigenic epitopes.
The oligosaccharide is fractionated by molecular size so the shell material sits in a narrow, defined range, since chain length governs how the finished complex behaves.
An iron(III) salt is reacted with the isomaltoside under controlled pH and temperature, precipitating an iron-hydroxide core that the carbohydrate encloses in a matrix rather than a simple shell.
Unbound iron and free carbohydrate are removed by diafiltration, and the bulk is controlled for endotoxin as a parenteral product must be.
Iron content, labile iron fraction, molecular weight distribution and pH are assayed to the marketing specification for each batch.
The solution is sterile-filtered, filled into single-use vials under aseptic conditions and terminally controlled to pharmacopoeial parenteral standards.
Getting Iron Isomaltoside 1000 from food.
The whole-food sources on file. A supplement closes the gap, it does not replace dinner.
A gram-for-gram figure (how much of each you would eat to match a dose) will appear here once it is sourced and reviewed. This page will not print a number it cannot cite.
The forms it comes in.
The essence, in one line each.
- Pooled randomised trials compared iron isomaltoside and ferumoxytol against iron sucrose in adults with low iron status, reporting haemoglobin and iron-store responses across the compared preparations.Meta-analysis. Shi et al., 2023 (African Health Sciences). PMID 38357109 ↗
- Iron isomaltoside given during surgery was compared with control for its effect on postoperative haemoglobin in knee replacement patients.Randomised trial. Yoo et al., 2021 (European Journal of Anaesthesiology). PMID 33259451 ↗
- Intravenous iron isomaltoside 1000 reduced the fall in postoperative haemoglobin among patients having elective urologic surgery compared with the control arm.Randomised trial. Goh et al., 2020 (Drug Design, Development and Therapy). PMID 33380788 ↗
- A published protocol setting out a randomised comparison of intravenous iron isomaltoside against oral iron in pregnancy; a protocol reports design and endpoints, not results.Randomised trial. Markova et al., 2020 (Trials). PMID 32843079 ↗
- Perioperative multidose tranexamic acid combined with erythropoietin and iron isomaltoside reduced blood loss measures in the surgical patients studied; iron isomaltoside was one component of a three-part regimen and its individual contribution cannot be separated out.Randomised trial. Ma et al., 2026 (Injury). PMID 42214827 ↗
- A drug-utilisation review describing how intravenous iron isomaltoside 1000 was prescribed and tolerated in a hospital population with low iron status; observational, so prescribing patterns are described rather than compared.Cohort study. Anil Kumar Purohit et al., 2026 (Cureus). PMID 42099357 ↗
- A single patient developed iron overload following intravenous iron isomaltoside administration, illustrating that parenteral iron bypasses the intestinal gate that normally limits iron entry.Case report. Hu et al., 2026 (Medicine). PMID 41517670 ↗
- In a preclinical model of myocardial ischaemia and reperfusion, iron isomaltoside affected the KLF4 signalling readouts the authors measured; a non-human mechanistic finding, not a clinical result.Animal study. Gong et al., 2025 (PLoS One). PMID 40471885 ↗
- A systematic review of intravenous iron given around the time of surgery for low iron status, in which iron isomaltoside is named among the preparations reviewed.Systematic review. Xue et al., 2026 (Journal of Clinical Anesthesia). PMID 41187664 ↗
- A pooled analysis of intravenous iron-carbohydrate complexes in adults with impaired cardiac pumping function and low iron status; iron isomaltoside is named among the complexes included.Meta-analysis. Sindone et al., 2023 (ESC Heart Failure). PMID 36178088 ↗
These are the studies our verdict leans on, chosen from the 10 we read for Iron Isomaltoside 1000. The full linked list is below.
The studies, linked.
11 sources behind our Iron Isomaltoside 1000 verdict: peer-reviewed studies and registered clinical trials. Every one links straight to PubMed, the journal, or ClinicalTrials.gov. Read them yourself.
- Clinical trialHiFIT Study: Interest of Intravenous Iron and Tranexamic Acid to Reduce Transfusion in Hip Fracture PatientsClinicalTrials.gov ↗PHASE3 · 419 participants · Terminated
- Clinical trialA Phase III, Randomized, Comparative, Open-label Study of Intravenous Iron Isomaltoside 1000 (Monofer®) Administered as Maintenance Therapy by Single or Repeated Bolus Injections in Comparison With Intravenous Iron Sucrose in Subjects With Stage 5 Chronic Kidney Disease on Dialysis Therapy (CKD-5D)ClinicalTrials.gov ↗PHASE3 · 351 participants · Completed
- Clinical trialA, Randomized Comparative, Open-Label Study of Intravenous Iron Isomaltoside 1000 (Monofer®) Administered by High Single Dose In-fusions or Standard Medical Care in Women After Postpartum HaemorrhageClinicalTrials.gov ↗PHASE3 · 200 participants · Completed
- Clinical trialA Randomized, Prospective, Double-Blind, Comparative Placebo-Controlled Study of Intravenous Iron Isomaltoside 1000 (Monofer®) Administered by Infusions to Iron-Deficient Blood DonorsClinicalTrials.gov ↗PHASE3 · 107 participants · Completed
- Clinical trialIntravenous Iron Supplement for Iron Deficiency in Cardiac Transplant RecipientsClinicalTrials.gov ↗PHASE2 · 102 participants · Completed
- Clinical trialA Randomized, Double-blind Comparative Study Comparing Ferric Carboxymaltose (Ferinject) and Iron Isomaltoside 1000 (Monofer) for Iron Substitution in Iron-deficiency AnemiaClinicalTrials.gov ↗PHASE4 · 26 participants · Completed
- Clinical trialOpen-label Pharmacokinetic Study of Iron Isomaltoside 1000 (Monofer®) Administered by 500 mg IV Bolus Injection or 1000 mg Intravenous Infusion to Patients With Non-hematological Malignancies Associated With Chemotherapy Induced Anaemia (CIA)(PK-CIA-04)ClinicalTrials.gov ↗PHASE1 · 16 participants · Completed
- Clinical trialA Randomized Open-label Trial Cross-over Trial of Iron Isomaltoside 1000 (Monofer®) Compared With Iron Sucrose (Venofer®) in Peritoneal Dialysis PatientsClinicalTrials.gov ↗NA · 16 participants · Terminated
- Clinical trialIntravenous Iron Isomaltoside Versus Iron Sucrose for Treatment of Iron Deficiency in Pregnancy: A Randomized Comparative TrialClinicalTrials.gov ↗PHASE3 · 280 participants · Recruiting
- Clinical trialA Randomised Phase II Trial of Iron Isomaltide Versus Oral Iron Supplement for Radiotherapy or Chemotherapy Associated Iron-deficiency Anemia Patients With Locally Advanced Nasopharyngeal CarcinomaClinicalTrials.gov ↗PHASE2 · 120 participants · Unknown
- Clinical trialA Phase III, Randomised, Double-blind, Comparative Study of Intravenous Iron Isomaltoside 1000 (Monofer®) Against Placebo in Subjects With Iron Deficiency Anaemia and Who Are Intol-erant or Unresponsive to Oral Iron TherapyClinicalTrials.gov ↗PHASE3 · Withdrawn
Evidence surfaced via Semantic Scholar (Allen Institute for AI) and ClinicalTrials.gov. Ranked by study type and citation weight, not cherry-picked.
Problems people have reported.
Read this carefully. These are 758 voluntary, unverified reactions reported to the FDA (openFDA). The number mostly reflects how popular Iron Isomaltoside 1000 is, not how risky it is. A report is not proof Iron Isomaltoside 1000 caused anything. It is a signal of what to watch for, nothing more.
Source: openFDA adverse-event reports. Voluntary reporting, not an incidence rate.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.