Drug · FAERS side-effect profile with label screen
Melatonin side effects: what 54,078 FDA adverse event reports show
Drug class
Not stated in label
Who reports
54,078 reports · 66% serious · 4,767 with death outcome · 59% female
openFDA FAERS counts, all years, deduplication not applied
Used for
For temporary relief of fatigue, irritability, insomnia, and exhaustion.
FDA label, Indications and Usage
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Reporting / coding artifact 9Lab value / disease marker 3No label text to screen 28
What the badges mean
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
- No label text to screen No validated FDA label was retrievable for this product, so the screen could not run. Disproportionality only.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only (and, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,126 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Congenital hiatus hernia | 160 | 1,034.1 767.3–1,393.7ROR 1,037.2 · calibrated p 7e-17 ✓ | 270.3 EB05 236.9 · IC025 +7.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=160 · ♀ 0% (drug 59%) | not reported in cached trials |
| Appendicolith | 265 | 918.7 735.7–1,147.2ROR 923.2 · calibrated p 1e-16 ✓ | 265.0 EB05 239.3 · IC025 +7.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=265 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Sleep disorder therapy | 99 | 444.1 332.4–593.4ROR 444.9 · calibrated p 6e-13 ✓ | 197.9 EB05 167.3 · IC025 +6.3 3/3 methods agree | Reporting / coding artifact | serious n=99 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Antacid therapy | 57 | 350.6 244.7–502.3ROR 350.9 · calibrated p 9e-12 ✓ | 172.6 EB05 138.2 · IC025 +5.7 3/3 methods agree | Reporting / coding artifact | serious n=57 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Analgesic therapy | 100 | 187.8 147.9–238.6ROR 188.2 · calibrated p 1e-9 ✓ | 123.3 EB05 104.3 · IC025 +5.9 3/3 methods agree | Reporting / coding artifact | serious n=100 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Malignant melanoma stage 0 | 55 | 169.1 123.1–232.3ROR 169.3 · calibrated p 4e-9 ✓ | 113.0 EB05 90.1 · IC025 +5.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=55 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Drug therapy | 94 | 161.5 126.9–205.5ROR 161.7 · calibrated p 4e-9 ✓ | 111.2 EB05 93.6 · IC025 +5.8 3/3 methods agree | Reporting / coding artifact | serious n=94 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Anticoagulant therapy | 56 | 98.0 73.0–131.4ROR 98.1 · calibrated p 2e-7 ✓ | 76.2 EB05 60.9 · IC025 +5.1 3/3 methods agree | Reporting / coding artifact | serious n=56 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Victim of child abuse | 48 | 93.4 68.1–128.0ROR 93.5 · calibrated p 4e-7 ✓ | 73.1 EB05 57.3 · IC025 +4.9 3/3 methods agree | Reporting / coding artifact | serious n=48 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Child abuse | 45 | 84.9 61.5–117.3ROR 85.0 · calibrated p 7e-7 ✓ | 67.7 EB05 52.7 · IC025 +4.8 3/3 methods agree | Reporting / coding artifact | serious n=45 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Epidural lipomatosis | 55 | 72.6 54.4–96.8ROR 72.6 · calibrated p 2e-6 ✓ | 59.9 EB05 47.8 · IC025 +4.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=55 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Malignant melanoma in situ | 88 | 29.0 23.4–36.0ROR 29.1 · calibrated p 4e-4 ✓ | 26.9 EB05 22.5 · IC025 +4.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=88 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Hyperphosphataemia | 145 | 28.4 24.0–33.6ROR 28.5 · calibrated p 4e-4 ✓ | 26.4 EB05 23.0 · IC025 +4.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=145 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Blood phosphorus increased | 185 | 28.2 24.3–32.7ROR 28.3 · calibrated p 4e-4 ✓ | 26.2 EB05 23.2 · IC025 +4.4 3/3 methods agree | Lab value / disease marker | serious n=184 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Bronchopulmonary aspergillosis allergic | 39 | 17.2 12.5–23.7ROR 17.2 · calibrated p 0.005 ✓ | 16.3 EB05 12.3 · IC025 +3.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=39 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Infusion site mass | 44 | 16.6 12.3–22.5ROR 16.6 · calibrated p 0.005 ✓ | 15.8 EB05 12.2 · IC025 +3.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=32 · ♀ 100% (drug 59%) · 100% consumer | not reported in cached trials |
| Clostridium test positive | 88 | 16.3 13.1–20.1ROR 16.3 · calibrated p 0.005 ✓ | 15.6 EB05 13.0 · IC025 +3.5 3/3 methods agree | Lab value / disease marker | serious n=88 · 100% clinician | not reported in cached trials |
| Stoma site infection | 47 | 14.6 10.9–19.5ROR 14.6 · calibrated p 0.009 ✓ | 13.9 EB05 10.7 · IC025 +3.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=41 · ♀ 0% (drug 59%) · 100% consumer | not reported in cached trials |
| Infusion site discharge | 62 | 14.5 11.3–18.7ROR 14.6 · calibrated p 0.009 ✓ | 13.9 EB05 11.2 · IC025 +3.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=41 · ♀ 100% (drug 59%) · 100% consumer | not reported in cached trials |
| Breath sounds abnormal | 177 | 14.4 12.4–16.7ROR 14.4 · calibrated p 0.008 ✓ | 13.9 EB05 12.2 · IC025 +3.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=175 · ♀ 0% (drug 59%) | not reported in cached trials |
| Benign prostatic hyperplasia | 179 | 13.8 11.9–16.1ROR 13.9 · calibrated p 0.010 ✓ | 13.3 EB05 11.8 · IC025 +3.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=179 · ♀ 0% (drug 59%) | not reported in cached trials |
| Total lung capacity decreased | 52 | 13.0 9.8–17.1ROR 13.0 · calibrated p 0.014 ✓ | 12.3 EB05 9.6 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=50 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Appendicitis | 298 | 12.8 11.4–14.4ROR 12.9 · calibrated p 0.013 ✓ | 12.4 EB05 11.2 · IC025 +3.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 11.1 · ♀ 8% (drug 59%) · 92% clinician | not reported in cached trials |
| Stoma site erythema | 57 | 12.1 9.3–15.8ROR 12.2 · calibrated p 0.018 ✓ | 11.6 EB05 9.1 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=47 · 100% consumer | not reported in cached trials |
| Aplastic anaemia | 156 | 11.9 10.1–13.9ROR 11.9 · calibrated p 0.018 ✓ | 11.4 EB05 10.0 · IC025 +3.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=156 · 100% clinician | not reported in cached trials |
| Blood uric acid increased | 163 | 11.2 9.6–13.1ROR 11.3 · calibrated p 0.022 ✓ | 10.9 EB05 9.5 · IC025 +3.2 3/3 methods agree | Lab value / disease marker | serious n=161 · ♀ 18% (drug 59%) | not reported in cached trials |
| Stoma site pain | 40 | 10.9 7.9–14.9ROR 10.9 · calibrated p 0.028 ✓ | 10.1 EB05 7.6 · IC025 +2.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=36 · ♀ 0% (drug 59%) · 100% consumer | not reported in cached trials |
| Intentional self-injury | 550 | 10.8 10.0–11.8ROR 10.9 · calibrated p 0.024 ✓ | 10.5 EB05 9.8 · IC025 +3.2 3/3 methods agree | Reporting / coding artifact | serious PRR 9.3 | not reported in cached trials |
| Freezing phenomenon | 98 | 10.8 8.9–13.2ROR 10.8 · calibrated p 0.026 ✓ | 10.4 EB05 8.7 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=75 · 70% consumer | not reported in cached trials |
| On and off phenomenon | 143 | 10.8 9.1–12.7ROR 10.8 · calibrated p 0.025 ✓ | 10.4 EB05 9.0 · IC025 +3.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=113 | not reported in cached trials |
| Stoma site discharge | 74 | 10.7 8.5–13.5ROR 10.7 · calibrated p 0.027 ✓ | 10.2 EB05 8.3 · IC025 +2.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=64 · 100% consumer | not reported in cached trials |
| Iron deficiency | 119 | 10.6 8.9–12.7ROR 10.6 · calibrated p 0.027 ✓ | 10.2 EB05 8.7 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=117 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Bronchiectasis | 177 | 10.6 9.1–12.2ROR 10.6 · calibrated p 0.027 ✓ | 10.2 EB05 9.0 · IC025 +3.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=177 · ♀ 19% (drug 59%) | not reported in cached trials |
| Myasthenia gravis | 201 | 10.1 8.8–11.6ROR 10.2 · calibrated p 0.031 ✓ | 9.8 EB05 8.7 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.9 · ♀ 21% (drug 59%) | not reported in cached trials |
| Infusion site haemorrhage | 82 | 10.0 8.1–12.5ROR 10.0 · calibrated p 0.034 ✓ | 9.6 EB05 7.9 · IC025 +2.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=56 · 100% consumer | NCT00668707: 1/356 (0.3%) on Melatonin; 1/353 (0.3%) control |
| Infusion site pruritus | 78 | 9.9 7.9–12.4ROR 9.9 · calibrated p 0.035 ✓ | 9.4 EB05 7.7 · IC025 +2.8 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=51 · ♀ 100% (drug 59%) | NCT01700959: 10/66 (15.2%) on Melatonin; 7/58 (12.1%) control |
| Infusion site bruising | 53 | 9.9 7.5–13.0ROR 9.9 · calibrated p 0.037 ✓ | 9.3 EB05 7.3 · IC025 +2.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=34 · ♀ 100% (drug 59%) · 100% consumer | not reported in cached trials |
| Juvenile idiopathic arthritis | 61 | 9.9 7.7–12.7ROR 9.9 · calibrated p 0.036 ✓ | 9.3 EB05 7.4 · IC025 +2.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=60 · ♀ 0% (drug 59%) · 100% clinician | not reported in cached trials |
| Aortic stenosis | 86 | 9.8 7.9–12.1ROR 9.8 · calibrated p 0.037 ✓ | 9.3 EB05 7.7 · IC025 +2.8 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=85 · ♀ 0% (drug 59%) | not reported in cached trials |
| Sedation complication | 61 | 9.7 7.5–12.5ROR 9.7 · calibrated p 0.039 ✓ | 9.1 EB05 7.3 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious n=59 · ♀ 100% (drug 59%) · 100% clinician | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Melatonin as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (2 of 40 signal terms matched).
- NCT01700959 — Melatonin Intervention For Neurocognitive Deficits in the St. Jude Lifetime Cohort (N=911, PHASE3; 68 AE terms posted; arms: Melatonin: NI Without DSOL; Placebo: NI Without DSOL; Melatonin: NI With DSOL; Placebo: NI With DSOL)
- NCT00668707 — Adjuvant Melatonin for Prevention of Lung Cancer Recurrence and Mortality (N=709, PHASE3; 323 AE terms posted; arms: Melatonin; Placebo)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Fatigue (tiredness) | 4,440 | 2.2 2.2–2.3ROR 2.3 · calibrated p 0.889 | 2.2 EB05 2.2 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.2 | NCT01700959: 2/62 (3.2%) on Melatonin; 1/58 (1.7%) control (serious AE) |
| Nausea | 3,762 | 1.9 1.8–1.9ROR 1.9 · calibrated p 0.897 | 1.8 EB05 1.8 · IC025 +0.8 | No label text to screen label has no adverse-reaction text | serious PRR 2.1 | NCT01700959: 1/62 (1.6%) on Melatonin; 2/68 (2.9%) control (serious AE) |
| Off label use (used outside approved label) | 3,431 | 1.5 1.5–1.6ROR 1.6 · calibrated p 0.687 | 1.5 EB05 1.5 · IC025 +0.6 | Reporting / coding artifact | serious PRR 1.8 | not reported in cached trials |
| Drug ineffective (drug did not work) | 3,207 | 0.9 0.9–1.0ROR 0.9 · calibrated p 0.268 | 0.9 EB05 0.9 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.3 | not reported in cached trials |
| Diarrhoea (diarrhea) | 3,027 | 1.8 1.8–1.9ROR 1.9 · calibrated p 0.875 | 1.8 EB05 1.8 · IC025 +0.8 | No label text to screen label has no adverse-reaction text | serious PRR 1.7 | NCT01700959: 1/68 (1.5%) control (serious AE) |
| Headache | 2,970 | 1.8 1.8–1.9ROR 1.9 · calibrated p 0.883 | 1.8 EB05 1.8 · IC025 +0.8 | No label text to screen label has no adverse-reaction text | serious PRR 2.1 | NCT01700959: 2/62 (3.2%) on Melatonin; 1/58 (1.7%) control (serious AE) |
| Dyspnoea (shortness of breath) | 2,589 | 1.8 1.7–1.8ROR 1.8 · calibrated p 0.839 | 1.8 EB05 1.7 · IC025 +0.8 | No label text to screen label has no adverse-reaction text | serious PRR 1.7 | NCT00668707: 1/356 (0.3%) on Melatonin; 1/353 (0.3%) control (serious AE) |
| Insomnia (trouble sleeping) | 2,515 | 3.7 3.5–3.8ROR 3.8 · calibrated p 0.415 | 3.7 EB05 3.5 · IC025 +1.8 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.4 | NCT01700959: 1/66 (1.5%) on Melatonin; 2/68 (2.9%) control (serious AE) |
| Fall | 2,435 | 2.9 2.7–3.0ROR 2.9 · calibrated p 0.647 | 2.8 EB05 2.7 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.5 | NCT00668707: 3/356 (0.8%) on Melatonin; 2/353 (0.6%) control |
| Pain | 2,356 | 1.5 1.4–1.5ROR 1.5 · calibrated p 0.647 | 1.5 EB05 1.4 · IC025 +0.5 | No label text to screen label has no adverse-reaction text | serious PRR 1.5 | NCT01700959: 1/68 (1.5%) control (serious AE) |
| Dizziness | 2,342 | 1.8 1.8–1.9ROR 1.9 · calibrated p 0.867 | 1.8 EB05 1.8 · IC025 +0.8 | No label text to screen label has no adverse-reaction text | serious PRR 1.9 | NCT01700959: 1/68 (1.5%) control (serious AE) |
| Vomiting | 2,234 | 1.9 1.8–1.9ROR 1.9 · calibrated p 0.881 | 1.8 EB05 1.8 · IC025 +0.8 | No label text to screen label has no adverse-reaction text | serious PRR 1.9 | NCT01700959: 1/62 (1.6%) on Melatonin; 1/68 (1.5%) control (serious AE) |
| Death | 2,164 | 1.0 0.9–1.0ROR 1.0 · calibrated p 0.289 | 1.0 EB05 0.9 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Outcome field, not a reaction | serious PRR 0.9 | NCT00668707: 37/356 (10.4%) on Melatonin; 37/353 (10.5%) control (serious AE) |
| Somnolence (drowsiness) | 1,933 | 3.8 3.6–3.9ROR 3.9 · calibrated p 0.406 | 3.7 EB05 3.6 · IC025 +1.8 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.3 | NCT01700959: 1/68 (1.5%) control (serious AE) |
| Asthenia (weakness) | 1,918 | 2.0 1.9–2.1ROR 2.0 · calibrated p 0.953 | 2.0 EB05 1.9 · IC025 +0.9 | No label text to screen label has no adverse-reaction text | serious PRR 1.8 | not reported in cached trials |
Unlabeled candidate signals
Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Melatonin?
In FDA FAERS, the most frequently co-reported reaction terms for Melatonin are fatigue, nausea, diarrhoea, headache, dyspnoea, insomnia. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Melatonin have an FDA boxed warning?
No. The FDA label retrieved for Melatonin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Melatonin causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 8951e5e9-5d8f-4808-b247-208760fae656, effective 20241017; matched on
openfda.generic_name.exact:"MELATONIN") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 1,166 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath - ClinicalTrials.gov API v2 (query
MELATONIN, results-bearing studies sorted by enrollment)
Page generated 2026-10-14. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.