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selenium Side Effects

Also known as: Selenium

Analysis of 4,079 adverse event reports submitted to the FDA from 2005 to 2025.

Total Reports

4,079

Death-Related

236

5.8% of reports

Hospitalizations

1,077

26.4% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

FATIGUE
467
HEADACHE
326
DIARRHOEA
308
NAUSEA
303
PAIN
280
ARTHRALGIA
257
DIZZINESS
250
DRUG INEFFECTIVE
234
DYSPNOEA
198
INSOMNIA
189
PAIN IN EXTREMITY
182
MUSCLE SPASMS
175
OFF LABEL USE
175
ANXIETY
174
WEIGHT DECREASED
170
ASTHENIA
169
PRURITUS
157
RASH
155
BACK PAIN
147
FALL
142

Who Reports Side Effects

Gender Distribution

Female 2,483 (65%)
Male 1,333 (35%)
Unknown 6

Age Distribution

0-17 77 (3%)
18-44 349 (13%)
45-64 970 (37%)
65-74 693 (27%)
75+ 517 (20%)

Reporting Trend by Year

2005 2025

Reactions in Death Reports

Top reactions reported in 236 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 113
DYSPNOEA 18
PNEUMONIA 17
FATIGUE 16
VOMITING 16
CONFUSIONAL STATE 15
ASTHENIA 14
ASCITES 13
SEIZURE 13
SEPSIS 13
FALL 12
MALIGNANT NEOPLASM PROGRESSION 12
DIARRHOEA 11
NAUSEA 11
RESPIRATORY FAILURE 11
CARDIAC ARREST 10
HYPOXIA 10
ILL-DEFINED DISORDER 10
LOSS OF CONSCIOUSNESS 10
MULTIPLE ORGAN DYSFUNCTION SYNDROME 10

Reactions in Hospitalization Reports

Top reactions in 1,077 reports where hospitalization was an outcome.

Reaction Reports
FATIGUE 123
NAUSEA 98
DIARRHOEA 94
PNEUMONIA 88
HEADACHE 79
DYSPNOEA 77
DIZZINESS 76
FALL 73
PAIN 71
PYREXIA 69
VOMITING 62
ARTHRALGIA 59
WEIGHT DECREASED 59
ASTHENIA 57
INSOMNIA 57
RASH 55
BACK PAIN 53
COUGH 51
DRUG INEFFECTIVE 50
INFECTION 50

Nearby — Related Medications

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What the FAERS Data Reveals About selenium Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 4,079 voluntary reports linked to selenium and its brand equivalents (Selenium), spanning 2005 through 2025. Of those, 236 (5.8%) listed death as an outcome and 1,077 (26.4%) 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, 65% were female and 35% male; age distribution skews toward 45-64, with 970 reports in that bracket. The single most reported reaction is fatigue with 467 submissions, followed by headache and diarrhoea.

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.