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melatonin Side Effects

Also known as: Melatonin

Analysis of 51,370 adverse event reports submitted to the FDA from 2004 to 2025.

Total Reports

51,370

Death-Related

4,506

8.8% of reports

Hospitalizations

17,241

33.6% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

FATIGUE
4,196
NAUSEA
3,592
OFF LABEL USE
3,225
DRUG INEFFECTIVE
3,031
DIARRHOEA
2,866
HEADACHE
2,798
DYSPNOEA
2,436
INSOMNIA
2,429
FALL
2,301
PAIN
2,252
DIZZINESS
2,219
VOMITING
2,123
DEATH
2,032
SOMNOLENCE
1,842
ASTHENIA
1,818
CONSTIPATION
1,800
ANXIETY
1,702
PNEUMONIA
1,622
ARTHRALGIA
1,517
CONDITION AGGRAVATED
1,483

Who Reports Side Effects

Gender Distribution

Female 28,004 (59%)
Male 19,382 (41%)
Unknown 27

Age Distribution

0-17 4,820 (14%)
18-44 5,859 (17%)
45-64 9,463 (28%)
65-74 7,011 (20%)
75+ 7,163 (21%)

Reporting Trend by Year

2004 2025

Reactions in Death Reports

Top reactions reported in 4,506 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 2,028
OFF LABEL USE 397
SEPSIS 361
NAUSEA 343
GENERAL PHYSICAL HEALTH DETERIORATION 329
MULTIPLE ORGAN DYSFUNCTION SYNDROME 328
VOMITING 318
COMPLETED SUICIDE 310
CONSTIPATION 303
ABDOMINAL PAIN 291
HYPONATRAEMIA 288
PNEUMONIA 285
ABDOMINAL DISTENSION 281
ASCITES 272
DYSPNOEA 256
CARDIOGENIC SHOCK 255
STRESS 249
CARDIAC ARREST 247
APPENDICITIS 246
APPENDICOLITH 244

Reactions in Hospitalization Reports

Top reactions in 17,241 reports where hospitalization was an outcome.

Reaction Reports
FALL 1,330
PNEUMONIA 1,273
DYSPNOEA 1,256
NAUSEA 1,186
FATIGUE 1,145
OFF LABEL USE 1,139
VOMITING 988
DIARRHOEA 960
SOMNOLENCE 847
ASTHENIA 789
PAIN 786
PYREXIA 785
HEADACHE 750
DRUG INEFFECTIVE 740
URINARY TRACT INFECTION 697
DIZZINESS 675
INTENTIONAL OVERDOSE 657
CONSTIPATION 614
HYPOTENSION 601
WEIGHT DECREASED 588

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What the FAERS Data Reveals About melatonin Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 51,370 voluntary reports linked to melatonin and its brand equivalents (Melatonin), spanning 2004 through 2025. Of those, 4,506 (8.8%) listed death as an outcome and 17,241 (33.6%) 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, 59% were female and 41% male; age distribution skews toward 45-64, with 9,463 reports in that bracket. The single most reported reaction is fatigue with 4,196 submissions, followed by nausea and off label use.

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.