GI side effects are a barrier to staying on traditional oral iron treatments29

Traditional oral iron treatments, such as ferrous salts (Fe2+), often cause GI side effects because they dissociate in the stomach

If you’re finding that patients often have GI issues when taking traditional oral iron, like ferrous salts (Fe2+), there’s a simple explanation:3,5,33

  • When ferrous salts dissociate in the stomach, they can bind together, creating clumps that are hard to absorb. In fact, nearly 90% of Fe2+ in ferrous salts goes unabsorbed.33
  • Unabsorbed Fe2+ oxidizes, which generates reactive oxygen species (ROS).3,5,33
  • ROS can cause irritation and damage when they reach the intestinal lining, contributing to GI discomfort.3,5,33

Additionally, free iron in the colon can have adverse impacts on the gut microbiome, adding to the inflammation with which IBD patients are already dealing.34

Unlike ferrous salts, which dissociate in the stomach, ACCRUFeR® (ferric maltol) dissociates upon uptake in the duodenum.2 This allows ACCRUFeR to deliver a low dose of elemental iron that can reverse IDA while minimizing risk for unmanageable GI side effects.2,3

Oral iron supplements come with downsides3,5,33

Up to


of people taking traditional oral iron report GI issues*,30,31

*A few examples of GI issues are: Heartburn, loss of appetite, stomach cramps, nausea, diarrhea, discolored stool, flatulence and constipation.30, 31

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Up to


of patients will not adhere to treatment due to adverse reactions.32

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Prescribe patients an oral iron they'll actually take1

In clinical studies, most patients taking ACCRUFeR (n=64) adhered to treatment during the 12-week randomized period and during the 52-week open label extension, leading to a 97% median compliance rate.1


1. Schmidt C, Ahmad T, Tulassay Z, et al. Ferric maltol therapy for iron deficiency anaemia in patients with inflammatory bowel disease: long-term extension data from a phase 3 study. Aliment Pharmacol Ther. 2016;44(3):259-270. doi:10.1111/apt.13665

2. ACCRUFeR® full prescribing information. Shield Therapeutics, 2023.

3. Stallmach A, Büning C. Ferric maltol (ST10): a novel oral iron supplement for the treatment of iron deficiency anemia in inflammatory bowel disease. Expert Opin Pharmacother. 2015;16(18):2859-2867. doi:10.1517/14656566.2015.1096929

4. European Medicines Agency. Accessed March 17, 2021. 

5. Gasche C, Ahmad T, Tulassay Z, et al. Ferric maltol is effective in correcting iron deficiency anemia in patients with inflammatory bowel disease: results from a phase-3 clinical trial program. Inflamm Bowel Dis. 2015;21(3):579-588. doi:10.1097/mib.0000000000000314

29. Lindgren S, Wikman O, Befrits R, et al. Intravenous iron sucrose is superior to oral iron sulphate for correcting anaemia and restoring iron stores in IBD patients: a randomized, controlled, evaluator-blind, multicentre study. Scand J Gastroenterol. 2009;44(7):838-845. doi:10.1080/00365520902839667

30. DeLoughery TG. Safety of oral and intravenous iron. Acta Haematologica. 2019;142(1):8-12. doi:10.1159/000496966

31. Tolkien Z, Stecher L, Mander AP, Pereira DI, Powell JJ. Ferrous sulfate supplementation causes significant gastrointestinal side-effects in adults: a systematic review and meta-analysis. PLoS One. 2015;10(2);e0117383. doi:10.1371/journal.pone.0117383

32. Cancelo-Hidalgo MJ, Castelo-Branco C, Palacios S, et al. Tolerability of different oral iron supplements: a systematic review. Curr Med Res Opin. 2013;29(4):291-303. doi:10.1185/03007995.2012.761599

33. Howaldt S, Domènech E, Martinez N, Schmidt C, Bokemeyer B. Long-term effectiveness of oral ferric maltol vs intravenous ferric carboxymaltose for the treatment of iron-deficiency anemia in patients with inflammatory bowel disease: A randomized controlled noninferiority trial. Inflamm Bowel Dis. 2021;28(3):373-384. doi:10.1093/ibd/izab073.

34. Ems T, et al. Biochemistry, Iron Absorption. StatPearls [Internet]; 2021.