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Ferrous Sulfate Side Effects

The most commonly reported side effects of ferrous sulfate include fatigue, diarrhoea, and dyspnoea, based on 57,969 FDA adverse event reports from 2004 to 2025. 2.8% of reports found the drug to be ineffective.

Ferrous Sulfate side effects

Percentages show how often each reaction appears relative to total reports for ferrous sulfate.

1
Fatigue5.9%3,415
2
Diarrhoea5.5%3,193
3
Dyspnoea4.9%2,843
4
Nausea4.9%2,817
5
Off Label Use4.4%2,547
6
Death4.2%2,441
7
Acute Kidney Injury3.7%2,140
8
Anaemia3.4%1,999
9
Pneumonia3.4%1,981
10
Headache3.4%1,974
11
Pain3.4%1,952
12
Asthenia3.4%1,950
13
Dizziness3.3%1,887
14
Fall3.2%1,843
15
Vomiting3.1%1,823

These are voluntary reports and do not establish that ferrous sulfate caused these reactions.

Report severity

77.4%Serious44,842 reports
45.2%Hospitalizations26,195 reports
11.9%Fatal6,870 reports

Seriousness is determined by the reporter, not by OpenClaim.

Ferrous Sulfate drug interactions

Other drugs that appear in adverse event reports alongside ferrous sulfate. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Lenalidomide6.2%3,585
2
Adalimumab3.4%1,995
3
Treprostinil3.2%1,846
4
Omeprazole3.1%1,800
5
Sodium-oxybate2.6%1,517
6
Esomeprazole2.1%1,216
7
Aspirin2.1%1,211
8
Infliximab2.1%1,210
9
Pantoprazole-sodium2.1%1,204
10
Rivaroxaban1.8%1,058
11
Lansoprazole1.7%1,011
12
Furosemide1.7%1,002
13
Apixaban1.7%962
14
Metformin1.5%886
15
Ambrisentan1.5%876

Taken alongside

1
Acetaminophen26.2%15,182
2
Aspirin24.3%14,107
3
Ergocalciferol23.5%13,632
4
Furosemide22.4%12,976
5
Omeprazole19.1%11,054
6
Atorvastatin-calcium17.7%10,235
7
Levothyroxine-sodium16.8%9,723
8
Albuterol16.3%9,430
9
Metoprolol14.9%8,633
10
Amlodipine14.6%8,458
11
Pantoprazole-sodium14.4%8,321
12
Folic-acid13.8%8,017
13
Gabapentin13.5%7,852
14
Metformin11.9%6,870
15
Cyanocobalamin11.5%6,659

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports ferrous sulfate side effects

58.0% of ferrous sulfate adverse event reports involve female patients and 35.2% involve male patients. The largest age group is elderly at 50%. These figures reflect who reports side effects, not underlying risk.

Sex

Female58.0%
Male35.2%
Unknown6.8%

Age group

< 21.5%
2–111.5%
12–172.0%
18–6444.6%
65+50.5%

What is ferrous sulfate used for

Conditions and purposes for which patients were taking ferrous sulfate when the adverse event was reported.

Abdominal DiscomfortAbdominal SymptomAbnormal FaecesAcute Kidney InjuryAdverse EventAffective DisorderAlopeciaAmnesiaAnaemiaAnaemia MacrocyticAnaemia NeonatalAnaemia Of Chronic DiseaseAnaemia Of Malignant DiseaseAnaemia Of PregnancyAnaemia Postoperative

Showing 15 of 440 indications

Ferrous Sulfate brand names and reporting trend

Ferrous Sulfate is sold under the brand name Folvron.

Brand names

Folvron59,942

Quarterly reports (20042025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking ferrous sulfate with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.