What the label lists and what reports show
Ferric maltol side effects
Ferric maltol's FDA label: “Most common adverse reactions (incidence > 1%) are flatulence, diarrhea, constipation, feces discolored, abdominal pain, nausea, vomiting and abdominal discomfort/distension.” FAERS holds 1,038 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is constipation (158 reports).
- No generic listed
Check it at the source: the ferric maltol FDA label on DailyMed (effective January 2, 2026, Shield TX (UK) Ltd); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of ACCRUFER?ACCRUFER may cause serious side effects, including: Increased risk of inflammatory bowel disease (IBD) flare. You should avoid taking ACCRUFER if you have inflammatory bowel disease (IBD) and are experiencing a flare. Too much iron stored in your body (iron overload). Your healthcare provider should check the iron level in your blood before you start and during treatment with ACCRUFER. Risk of overdose in children due to accidental swallowing. Accidental overdose of iron-containing products is a leading cause of death from poisoning in children under 6. Keep ACCRUFER in a safe place and out of the reach of children. The most common side effects of ACCRUFER include: gas diarrhea constipation discolored stools stomach pain nausea vomiting stomach area discomfort or bloating These are not all the possible side effects of ACCRUFER. Call your doctor for medical advice about side effects. […]
Source: FDA drug label, Shield TX (UK) Ltd, effective January 2, 2026 (SPL set 367ac157-2d25-4f34-99ce-b126e0f03851), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence > 1%) are flatulence, diarrhea, constipation, feces discolored, abdominal pain, nausea, vomiting and abdominal discomfort/distension.
Table 1. Adverse Reactions Reported by ≥1% of Patients Treated with ACCRUFER During Placebo-Controlled Period of Pooled Studies (Studies AEGIS1/2 and AEGIS 3)
| Reaction | ACCRUFER 30 mg Twice Daily (N = 175) | Placebo (N = 120) |
|---|---|---|
| Flatulence | 4.6% | 0.0% |
| Diarrhea | 4.0% | 1.7% |
| Constipation | 4.0% | 0.8% |
| Feces discolored | 4.0% | 0.8% |
| Abdominal pain | 2.9% | 2.5% |
| Nausea | 1.7% | 0.8% |
| Vomiting | 1.7% | 0.0% |
| Abdominal discomfort | 1.1% | 0.0% |
| Abdominal distension | 1.1% | 0.0% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are described elsewhere in the labeling: Increased Risk of Inflammatory Bowel Disease Flare [see Warnings and Precautions ( 5.1 )] Iron Overload [see Warnings and Precautions ( 5.2 )] Most common adverse reactions (incidence > 1%) are flatulence, diarrhea, constipation, feces discolored, abdominal pain, nausea, vomiting and abdominal discomfort/distension. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Shield Therapeutics Inc at 1-888-963-6267 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data described below reflect exposure to ACCRUFER in 175 adult patients in the placebo-controlled phase of three randomized studies conducted in patients with anemia and quiescent inflammatory bowel disease (IBD) (Studies AEGIS 1 & 2) or non-dialysis dependent chronic kidney disease (CKD) (AEGIS 3). The pooled patient population had a mean age of 58 years, 67.4% were female (n=118), and 81.7% (n=143) were Caucasian. …
Source: FDA drug label, Shield TX (UK) Ltd, effective January 2, 2026 (SPL set 367ac157-2d25-4f34-99ce-b126e0f03851), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,038 reports list ferric maltol among the medicines taken, each a report of something that happened, not proof the medicine caused it; 37 are coded as a death and 84 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 19 reactions below, 8 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Ferric maltol: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions