ferrous sulfate Side Effects
Also known as: Feosol, Fer-In-Sol
Analysis of 47,788 adverse event reports submitted to the FDA from 1995 to 2025.
Total Reports
47,788
Death-Related
5,418
11.3% of reports
Hospitalizations
20,748
43.4% of reports
Top Indication
Product Used For Unknown Indication
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 5,418 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 2,335 |
| DYSPNOEA | 397 |
| ACUTE KIDNEY INJURY | 386 |
| PNEUMONIA | 361 |
| RENAL FAILURE | 304 |
| ANAEMIA | 265 |
| GASTROINTESTINAL HAEMORRHAGE | 242 |
| FATIGUE | 237 |
| SEPSIS | 237 |
| CHRONIC KIDNEY DISEASE | 232 |
| ASTHENIA | 223 |
| FALL | 218 |
| HYPOTENSION | 210 |
| NAUSEA | 206 |
| RESPIRATORY FAILURE | 206 |
| OFF LABEL USE | 204 |
| CARDIAC ARREST | 203 |
| DIARRHOEA | 201 |
| VOMITING | 195 |
| CARDIAC FAILURE CONGESTIVE | 169 |
Reactions in Hospitalization Reports
Top reactions in 20,748 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| DYSPNOEA | 1,732 |
| PNEUMONIA | 1,597 |
| DIARRHOEA | 1,396 |
| ACUTE KIDNEY INJURY | 1,375 |
| ANAEMIA | 1,343 |
| FATIGUE | 1,210 |
| FALL | 1,203 |
| NAUSEA | 1,180 |
| ASTHENIA | 1,098 |
| VOMITING | 1,028 |
| GASTROINTESTINAL HAEMORRHAGE | 968 |
| PYREXIA | 920 |
| HYPOTENSION | 856 |
| OFF LABEL USE | 844 |
| PAIN | 832 |
| URINARY TRACT INFECTION | 829 |
| DIZZINESS | 828 |
| HEADACHE | 746 |
| HAEMOGLOBIN DECREASED | 715 |
| WEIGHT DECREASED | 712 |
Nearby — Related Medications
What the FAERS Data Reveals About ferrous sulfate Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 47,788 voluntary reports linked to ferrous sulfate and its brand equivalents (Feosol, Fer-In-Sol), spanning 1995 through 2025. Of those, 5,418 (11.3%) listed death as an outcome and 20,748 (43.4%) involved hospitalization. The most common indication reported alongside adverse events was Product Used For Unknown Indication.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 62% were female and 37% male; age distribution skews toward 75+, with 9,412 reports in that bracket. The single most reported reaction is fatigue with 3,325 submissions, followed by diarrhoea and nausea.
FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice — speak with a licensed clinician about any side-effect concerns.
Read our methodology — how this data is sourced, computed, and verified.