Overview
- Researchers analyzing health records of about 130,000 adults with chronic insomnia reported roughly an 89% higher five‑year risk of heart‑failure hospitalization among some 65,000 long‑term melatonin users compared with non‑users.
- The observational study, led by Ekenedilichukwu Nnadi and presented at an American Heart Association meeting, also noted higher all‑cause mortality in users over five years in the data reviewed.
- Authors and independent specialists stress the results do not prove causation and highlight key limitations, including lack of dose information, no randomization, and potential confounding such as insomnia severity.
- Sleep physicians say widespread, unsupervised use—often extending to children and adolescents—underscores the need for medical guidance and for research that clarifies long‑term cardiovascular safety.
- Clinicians and pharmacists urge regulators to reassess over‑the‑counter availability and labeling, with some calling on the European Medicines Agency to add warnings as countries differ on access and dosing thresholds.