Long-term safety is unclear: one study linked regular use to a 90% higher chance of heart failure, but did not prove it caused harm.
Prevention reports on a study presented by the American Heart Association in 2025. It looked at adults wit
Melatonin prescriptions lasting over a year were linked to an 89% higher heart failure risk over five years, but this does not prove cause.
The analysis covered health records from more than 130,000 adults across several countries. They ha