Case Report: Intentional massive melatonin ingestion (450 mg) in an adolescent female
- 1Department of Surgery, Monash University , , ,
- 2Surgery Education and Researching Network (SERGN), Universal Scientific Education and Research Network (USERN) , , ,
- 3Razi Herbal Medicines Research Center, Lorestan University of Medical Sciences , ,
Abstract
Over-the-counter (OTC) melatonin is widely perceived as benign, yet its unregulated, high-dose formulations create an accessible means of self-harm for adolescents, and reports of intentional overdose have risen alongside a well-documented surge in pediatric exposures. We report a 16-year-old female who intentionally ingested 450 mg of melatonin (90 × 5 mg tablets), a 90-fold supratherapeutic dose, and synthesize this case against the published literature on melatonin overdose, suicidality, and toxicokinetics. She presented 2.5 h post-ingestion with marked somnolence (Glasgow Coma Scale 13/15) and heart rate of 62 beats/min. Venous blood gas showed a mild, respiratory-compensated metabolic acidosis (pH 7.34, HCO3 15.6 mmol/L), with mild hyponatremia and stress leukocytosis. Hepatic, renal, and coagulation studies and a 12-lead electrocardiogram were normal, and a comprehensive toxicology screen was negative, consistent with an isolated exposure (Poison Severity Score Grade 1, Minor). She was medically cleared within 14.5 h of ingestion but, given persistent suicidal ideation on psychiatric evaluation, was transferred to inpatient psychiatric care at 20.5 h post-ingestion. This case, together with a review of published case reports, cohort data, and toxicokinetic evidence, indicates that massive isolated melatonin ingestion typically produces self-limited sedation, consistent with saturable hepatic CYP1A2-mediated clearance, alongside mild, transient metabolic derangement without organ injury. Population-level and case-level evidence converge, however, on a critical message for clinicians: low physiological toxicity does not indicate low psychiatric risk, and every adolescent presenting after intentional OTC chronobiotic ingestion warrants formal psychiatric evaluation regardless of how benign the medical course appears.
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BibTeX
@article{miran2026case,
title = {{Case Report: Intentional massive melatonin ingestion (450 mg) in an adolescent female}},
author = {Sepehr Miran and Bahar Amiri and Peyman Astaraki and Arian Karimi Rouzbahani},
journal = {Frontiers in toxicology},
year = {2026},
month = oct,
doi = {10.3389/ftox.2026.1958318},
url = {https://europepmc.org/article/PMC/PMC13719137},
note = {CC BY},
}
RIS
TY - JOUR
TI - Case Report: Intentional massive melatonin ingestion (450 mg) in an adolescent female
AU - Sepehr Miran
AU - Bahar Amiri
AU - Peyman Astaraki
AU - Arian Karimi Rouzbahani
PY - 2026
DA - 2026/10/16
JO - Frontiers in toxicology
DO - 10.3389/ftox.2026.1958318
UR - https://europepmc.org/article/PMC/PMC13719137
AB - Over-the-counter (OTC) melatonin is widely perceived as benign, yet its unregulated, high-dose formulations create an accessible means of self-harm for adolescents, and reports of intentional overdose have risen alongside a well-documented surge in pediatric exposures. We report a 16-year-old female who intentionally ingested 450 mg of melatonin (90 × 5 mg tablets), a 90-fold supratherapeutic dose, and synthesize this case against the published literature on melatonin overdose, suicidality, and toxicokinetics. She presented 2.5 h post-ingestion with marked somnolence (Glasgow Coma Scale 13/15) and heart rate of 62 beats/min. Venous blood gas showed a mild, respiratory-compensated metabolic acidosis (pH 7.34, HCO3 15.6 mmol/L), with mild hyponatremia and stress leukocytosis. Hepatic, renal, and coagulation studies and a 12-lead electrocardiogram were normal, and a comprehensive toxicology screen was negative, consistent with an isolated exposure (Poison Severity Score Grade 1, Minor). She was medically cleared within 14.5 h of ingestion but, given persistent suicidal ideation on psychiatric evaluation, was transferred to inpatient psychiatric care at 20.5 h post-ingestion. This case, together with a review of published case reports, cohort data, and toxicokinetic evidence, indicates that massive isolated melatonin ingestion typically produces self-limited sedation, consistent with saturable hepatic CYP1A2-mediated clearance, alongside mild, transient metabolic derangement without organ injury. Population-level and case-level evidence converge, however, on a critical message for clinicians: low physiological toxicity does not indicate low psychiatric risk, and every adolescent presenting after intentional OTC chronobiotic ingestion warrants formal psychiatric evaluation regardless of how benign the medical course appears.
SN - 2673-3080
ER -