Drug · FAERS side-effect profile with label screen
Ferrous side effects: what 49,893 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Ferrous Sulfate (Ferrous Sulfate)
closest FDA label found for this product string; brand list suppressed because the label is a related product, not an exact match
Who reports
49,893 reports · 75% serious · 5,593 with death outcome · 63% female
openFDA FAERS counts, all years, deduplication not applied
Used for
SUGGESTED USE:
FDA label, Indications and Usage
Boxed warning
Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6. Keep this product out of reach of children. In case of accidental overdose, call a doctor or Poison Control Center immediately.
FDA label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Reporting / coding artifact 3Lab value / disease marker 5No label text to screen 32
What the badges mean
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
- No label text to screen No validated FDA label was retrievable for this product, so the screen could not run. Disproportionality only.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only (and, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,137 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Pulmonary malformation | 50 | 68.9 51.1–93.0ROR 69.0 · calibrated p 3e-6 ✓ | 58.0 EB05 45.7 · IC025 +4.8 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=50 · ♀ 100% (drug 63%) · 100% clinician | not reported in cached trials |
| Gastrointestinal tract mucosal pigmentation | 35 | 63.2 44.3–90.2ROR 63.2 · calibrated p 6e-6 ✓ | 53.4 EB05 40.2 · IC025 +4.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=31 · 100% clinician | not reported in cached trials |
| Chronic kidney disease-mineral and bone disorder | 101 | 43.5 35.4–53.3ROR 43.5 · calibrated p 4e-5 ✓ | 39.1 EB05 33.1 · IC025 +4.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=101 | not reported in cached trials |
| Nephrogenic anaemia | 387 | 37.9 34.1–42.0ROR 38.1 · calibrated p 7e-5 ✓ | 34.7 EB05 31.9 · IC025 +4.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=387 | not reported in cached trials |
| Hyperparathyroidism secondary | 190 | 34.0 29.4–39.4ROR 34.1 · calibrated p 1e-4 ✓ | 31.4 EB05 27.8 · IC025 +4.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=189 | not reported in cached trials |
| Foetal disorder | 35 | 18.1 12.9–25.4ROR 18.1 · calibrated p 0.004 ✓ | 17.2 EB05 12.8 · IC025 +3.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=35 · ♀ 0% (drug 63%) · 100% clinician | not reported in cached trials |
| Rebound acid hypersecretion | 104 | 14.7 12.1–17.9ROR 14.7 · calibrated p 0.008 ✓ | 14.2 EB05 12.0 · IC025 +3.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=104 | not reported in cached trials |
| Blood loss anaemia | 72 | 14.0 11.1–17.7ROR 14.0 · calibrated p 0.010 ✓ | 13.4 EB05 11.0 · IC025 +3.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=72 | not reported in cached trials |
| End stage renal disease | 573 | 13.5 12.4–14.6ROR 13.6 · calibrated p 0.010 ✓ | 13.0 EB05 12.2 · IC025 +3.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 10.0 | not reported in cached trials |
| Iron deficiency anaemia | 273 | 12.8 11.4–14.5ROR 12.9 · calibrated p 0.013 ✓ | 12.4 EB05 11.2 · IC025 +3.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.8 | not reported in cached trials |
| Haemorrhagic anaemia | 130 | 12.6 10.6–15.0ROR 12.6 · calibrated p 0.015 ✓ | 12.2 EB05 10.5 · IC025 +3.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=130 | not reported in cached trials |
| Essential hypertension | 58 | 9.6 7.4–12.5ROR 9.6 · calibrated p 0.040 ✓ | 9.1 EB05 7.2 · IC025 +2.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=54 | not reported in cached trials |
| Sinus node dysfunction | 40 | 9.4 6.8–12.8ROR 9.4 · calibrated p 0.045 ✓ | 8.7 EB05 6.5 · IC025 +2.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=41 · 100% clinician | not reported in cached trials |
| Infusion site discharge | 36 | 9.0 6.5–12.5ROR 9.0 · calibrated p 0.051 | 8.3 EB05 6.1 · IC025 +2.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | ♀ 100% (drug 63%) · 100% consumer | not reported in cached trials |
| Periodontitis | 45 | 9.0 6.7–12.1ROR 9.0 · calibrated p 0.050 | 8.4 EB05 6.4 · IC025 +2.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=45 · ♀ 0% (drug 63%) · 100% clinician | not reported in cached trials |
| Blood chloride increased | 36 | 8.9 6.4–12.4ROR 8.9 · calibrated p 0.053 | 8.2 EB05 6.1 · IC025 +2.4 3/3 methods agree | Lab value / disease marker | serious n=31 · 100% clinician | not reported in cached trials |
| Iron deficiency | 92 | 8.9 7.2–10.9ROR 8.9 · calibrated p 0.050 | 8.5 EB05 7.1 · IC025 +2.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=78 | not reported in cached trials |
| Chronic kidney disease | 1,476 | 8.2 7.8–8.7ROR 8.4 · calibrated p 0.056 | 8.1 EB05 7.7 · IC025 +2.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.3 | not reported in cached trials |
| Blood iron decreased | 224 | 8.1 7.1–9.3ROR 8.1 · calibrated p 0.064 | 7.9 EB05 7.0 · IC025 +2.8 3/3 methods agree | Lab value / disease marker | serious PRR 5.7 | not reported in cached trials |
| Infusion site haemorrhage | 59 | 7.8 6.0–10.0ROR 7.8 · calibrated p 0.077 | 7.3 EB05 5.8 · IC025 +2.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=34 · ♀ 100% (drug 63%) · 100% consumer | NCT00982007: 1/246 (0.4%) on Ferrous (serious AE) |
| Hypervolaemia | 87 | 7.7 6.3–9.6ROR 7.7 · calibrated p 0.076 | 7.4 EB05 6.1 · IC025 +2.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=85 | not reported in cached trials |
| Infusion site infection | 39 | 7.3 5.3–10.1ROR 7.3 · calibrated p 0.094 | 6.7 EB05 5.1 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | ♀ 100% (drug 63%) · 100% consumer | not reported in cached trials |
| Hypovolaemia | 100 | 7.3 6.0–8.9ROR 7.3 · calibrated p 0.090 | 7.0 EB05 5.9 · IC025 +2.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=98 | not reported in cached trials |
| Lower gastrointestinal haemorrhage | 118 | 6.8 5.6–8.1ROR 6.8 · calibrated p 0.111 | 6.5 EB05 5.6 · IC025 +2.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.2 | NCT00982007: 1/246 (0.4%) on Ferrous (serious AE) |
| Upper gastrointestinal haemorrhage | 268 | 6.8 6.0–7.6ROR 6.8 · calibrated p 0.109 | 6.6 EB05 6.0 · IC025 +2.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.2 | NCT00982007: 1/246 (0.4%) on Ferrous (serious AE) |
| Hypophosphataemia | 115 | 6.7 5.5–8.0ROR 6.7 · calibrated p 0.116 | 6.4 EB05 5.5 · IC025 +2.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.3 · ♀ 88% (drug 63%) | not reported in cached trials |
| Vascular device infection | 70 | 6.6 5.2–8.4ROR 6.6 · calibrated p 0.121 | 6.3 EB05 5.1 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=70 | not reported in cached trials |
| Respiratory symptom | 43 | 6.5 4.8–8.8ROR 6.5 · calibrated p 0.128 | 6.1 EB05 4.7 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=39 · ♀ 0% (drug 63%) · 100% clinician | not reported in cached trials |
| Exposure via breast milk | 60 | 6.5 5.1–8.4ROR 6.5 · calibrated p 0.126 | 6.2 EB05 5.0 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious n=59 · ♀ 100% (drug 63%) | not reported in cached trials |
| Maternal exposure during breast feeding | 60 | 6.5 5.0–8.4ROR 6.5 · calibrated p 0.126 | 6.2 EB05 4.9 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious n=56 · ♀ 100% (drug 63%) | not reported in cached trials |
| Red cell distribution width increased | 63 | 6.4 5.0–8.3ROR 6.5 · calibrated p 0.129 | 6.1 EB05 4.9 · IC025 +2.2 3/3 methods agree | Lab value / disease marker | serious n=56 | not reported in cached trials |
| Right ventricular failure | 107 | 6.4 5.3–7.8ROR 6.5 · calibrated p 0.127 | 6.2 EB05 5.3 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.9 | not reported in cached trials |
| Device infusion issue | 37 | 6.4 4.6–8.9ROR 6.4 · calibrated p 0.135 | 5.9 EB05 4.5 · IC025 +2.0 3/3 methods agree | Reporting / coding artifact | ♀ 100% (drug 63%) · 100% consumer | not reported in cached trials |
| Transfusion | 148 | 6.0 5.1–7.0ROR 6.0 · calibrated p 0.153 | 5.8 EB05 5.1 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.7 | not reported in cached trials |
| Infective pulmonary exacerbation of cystic fibrosis | 77 | 6.0 4.8–7.5ROR 6.0 · calibrated p 0.157 | 5.7 EB05 4.7 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=67 | not reported in cached trials |
| Acute kidney injury (sudden kidney damage) | 2,125 | 5.9 5.7–6.2ROR 6.1 · calibrated p 0.141 | 5.9 EB05 5.6 · IC025 +2.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.5 | not reported in cached trials |
| Full blood count abnormal | 146 | 5.9 5.0–6.9ROR 5.9 · calibrated p 0.159 | 5.7 EB05 5.0 · IC025 +2.2 3/3 methods agree | Lab value / disease marker | serious PRR 5.2 | not reported in cached trials |
| Blood magnesium decreased | 118 | 5.8 4.8–7.0ROR 5.8 · calibrated p 0.166 | 5.6 EB05 4.8 · IC025 +2.2 3/3 methods agree | Lab value / disease marker | serious PRR 4.4 | not reported in cached trials |
| Acute respiratory failure | 261 | 5.8 5.1–6.5ROR 5.8 · calibrated p 0.164 | 5.7 EB05 5.1 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.4 | NCT00982007: 1/245 (0.4%) on Ferrous (serious AE) |
| Pre-existing condition improved | 86 | 5.8 4.7–7.2ROR 5.8 · calibrated p 0.168 | 5.6 EB05 4.6 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=53 | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Ferrous as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (4 of 40 signal terms matched).
- NCT00982007 — Efficacy and Safety of Intravenous Ferric Carboxymaltose (FCM) in Patients With Iron Deficiency Anemia (IDA) (N=997, PHASE3; 47 AE terms posted; arms: Cohort 1 (Group A) - Ferric Carboxymalto; Cohort 1 (Group B) - Ferrous Sulfate; Cohort 2 (Group C) - Ferric Carboxymalto; Cohort 2 (Group D) - IV Iron (Standard o)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Fatigue (tiredness) | 3,518 | 1.9 1.8–2.0ROR 2.0 · calibrated p 0.930 | 1.9 EB05 1.8 · IC025 +0.9 | No label text to screen label has no adverse-reaction text | serious PRR 1.8 | NCT00982007: 1/246 (0.4%) on Ferrous (serious AE) |
| Diarrhoea (diarrhea) | 3,271 | 2.1 2.1–2.2ROR 2.2 · calibrated p 0.941 | 2.1 EB05 2.1 · IC025 +1.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.0 | not reported in cached trials |
| Nausea | 2,879 | 1.5 1.5–1.6ROR 1.6 · calibrated p 0.685 | 1.5 EB05 1.5 · IC025 +0.6 | No label text to screen label has no adverse-reaction text | serious PRR 1.6 | NCT00982007: 5/253 (2.0%) on Ferrous |
| Dyspnoea (shortness of breath) | 2,867 | 2.1 2.1–2.2ROR 2.2 · calibrated p 0.950 | 2.1 EB05 2.1 · IC025 +1.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 1.9 | not reported in cached trials |
| Off label use (used outside approved label) | 2,442 | 1.2 1.1–1.2ROR 1.2 · calibrated p 0.434 | 1.2 EB05 1.1 · IC025 +0.2 | Reporting / coding artifact | serious PRR 1.2 | not reported in cached trials |
| Death | 2,442 | 1.2 1.1–1.2ROR 1.2 · calibrated p 0.441 | 1.2 EB05 1.2 · IC025 +0.2 | Outcome field, not a reaction boxed warning mentions mortality | serious PRR 0.9 | NCT00982007: 1/253 (0.4%) on Ferrous (serious AE) |
| Acute kidney injury (sudden kidney damage) | 2,125 | 5.9 5.7–6.2ROR 6.1 · calibrated p 0.141 | 5.9 EB05 5.6 · IC025 +2.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.5 | not reported in cached trials |
| Headache | 2,055 | 1.4 1.3–1.4ROR 1.4 · calibrated p 0.573 | 1.4 EB05 1.3 · IC025 +0.4 | No label text to screen label has no adverse-reaction text | serious PRR 1.4 | not reported in cached trials |
| Anaemia (low red blood cells) | 2,042 | 4.5 4.3–4.7ROR 4.7 · calibrated p 0.272 | 4.5 EB05 4.3 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.5 | NCT00982007: 1/246 (0.4%) on Ferrous (serious AE) |
| Pneumonia (lung infection) | 2,039 | 2.7 2.5–2.8ROR 2.7 · calibrated p 0.721 | 2.6 EB05 2.6 · IC025 +1.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.1 | NCT00982007: 1/246 (0.4%) on Ferrous (serious AE) |
| Asthenia (weakness) | 2,002 | 2.2 2.1–2.3ROR 2.3 · calibrated p 0.906 | 2.2 EB05 2.2 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.0 | not reported in cached trials |
| Pain | 1,981 | 1.4 1.3–1.4ROR 1.4 · calibrated p 0.554 | 1.4 EB05 1.3 · IC025 +0.4 | No label text to screen label has no adverse-reaction text | serious PRR 1.3 | NCT00982007: 1/253 (0.4%) on Ferrous (serious AE) |
| Dizziness | 1,968 | 1.7 1.6–1.7ROR 1.7 · calibrated p 0.763 | 1.7 EB05 1.6 · IC025 +0.7 | No label text to screen label has no adverse-reaction text | serious PRR 1.6 | not reported in cached trials |
| Vomiting | 1,857 | 1.7 1.6–1.7ROR 1.7 · calibrated p 0.764 | 1.7 EB05 1.6 · IC025 +0.7 | No label text to screen label has no adverse-reaction text | serious PRR 1.5 | not reported in cached trials |
| Fall | 1,840 | 2.3 2.2–2.4ROR 2.4 · calibrated p 0.865 | 2.3 EB05 2.2 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 1.9 | not reported in cached trials |
Unlabeled candidate signals
Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.
✓ A hand-written Bradford Hill causality assessment exists for this drug: Gentamicin Sulfate ↔ Renal Failure.
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Ferrous?
In FDA FAERS, the most frequently co-reported reaction terms for Ferrous are fatigue, diarrhoea, nausea, dyspnoea, acute kidney injury, headache. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Ferrous have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6. Keep this product out of reach of children. In case of accidental overdose, call a doctor or Poison Control Center immediately.
Do FAERS signals prove that Ferrous causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 5514d582-19b5-4f1e-b794-f790afb8211c, effective 20241226; matched on
openfda.generic_name.exact:"FERROUS SULFATE") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 1,177 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath - ClinicalTrials.gov API v2 (query
FERROUS, results-bearing studies sorted by enrollment)
Page generated 2026-10-14. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.