Scientists have discovered a surprising link between long-term melatonin use and heart failure in patients with chronic insomnia.
Marketed as "nature's sleep switch", melatonin has become a nightly habit for millions, but new research suggests it may have negative effects on the heart.
These findings are based on a review of more than 130,000 adults with insomnia, presented at the American Heart Association's Scientific Sessions 2025.
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Author's summary: Melatonin may harm the heart in insomnia patients.