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magnesium oxide Side Effects

Also known as: Mag-Ox

Analysis of 39,831 adverse event reports submitted to the FDA from 2002 to 2025.

Total Reports

39,831

Death-Related

6,280

15.8% of reports

Hospitalizations

19,832

49.8% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

NAUSEA
2,795
DIARRHOEA
2,580
FATIGUE
2,419
DYSPNOEA
2,054
PNEUMONIA
2,029
OFF LABEL USE
1,940
PYREXIA
1,829
VOMITING
1,666
DEATH
1,601
HEADACHE
1,598
ANAEMIA
1,465
PAIN
1,453
DECREASED APPETITE
1,440
CONSTIPATION
1,404
DRUG INEFFECTIVE
1,401
FALL
1,335
ASTHENIA
1,302
MALAISE
1,301
DIZZINESS
1,300
CONDITION AGGRAVATED
1,147

Who Reports Side Effects

Gender Distribution

Female 20,905 (56%)
Male 16,312 (44%)
Unknown 25

Age Distribution

0-17 658 (2%)
18-44 2,526 (9%)
45-64 8,267 (29%)
65-74 8,659 (30%)
75+ 8,409 (29%)

Reporting Trend by Year

2002 2025

Reactions in Death Reports

Top reactions reported in 6,280 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 1,595
PNEUMONIA 613
SEPSIS 397
DYSPNOEA 390
MALIGNANT NEOPLASM PROGRESSION 386
NAUSEA 376
INTERSTITIAL LUNG DISEASE 371
PYREXIA 362
ANAEMIA 361
OFF LABEL USE 347
VOMITING 318
RESPIRATORY FAILURE 311
DIARRHOEA 303
PLATELET COUNT DECREASED 299
CONDITION AGGRAVATED 286
DECREASED APPETITE 282
CONSTIPATION 275
DISEASE PROGRESSION 252
ACUTE KIDNEY INJURY 249
ABDOMINAL PAIN 218

Reactions in Hospitalization Reports

Top reactions in 19,832 reports where hospitalization was an outcome.

Reaction Reports
PNEUMONIA 1,642
NAUSEA 1,560
PYREXIA 1,426
DIARRHOEA 1,395
DYSPNOEA 1,298
VOMITING 1,107
ANAEMIA 1,092
FATIGUE 1,048
OFF LABEL USE 988
DECREASED APPETITE 897
FALL 878
ABDOMINAL PAIN 847
PAIN 824
MALAISE 820
HEADACHE 785
CONSTIPATION 776
ASTHENIA 772
ACUTE KIDNEY INJURY 765
CONDITION AGGRAVATED 736
DEHYDRATION 701

Nearby — Related Medications

Compare magnesium oxide vs ascorbic acid →

What the FAERS Data Reveals About magnesium oxide Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 39,831 voluntary reports linked to magnesium oxide and its brand equivalents (Mag-Ox), spanning 2002 through 2025. Of those, 6,280 (15.8%) listed death as an outcome and 19,832 (49.8%) 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, 56% were female and 44% male; age distribution skews toward 65-74, with 8,659 reports in that bracket. The single most reported reaction is nausea with 2,795 submissions, followed by diarrhoea and fatigue.

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.