People with chronic insomnia who used melatonin long term had a roughly 90% higher risk of developing heart failure over five years, according to a large preliminary study. The findings do not prove melatonin causes heart problems, but they raise new questions about the safety of taking the popu...

Source: [ScienceDaily](https://www.sciencedaily.com/releases/2026/08/260829035228.htm)

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