Does Long-Term Melatonin Use Affect Heart Health? What Parents Should Know

Melatonin is widely used as a sleep aid, but new preliminary research has raised questions about its long-term use and cardiovascular health. In the video above, Dr. Luke Reinhart explains what researchers found, what the study cannot tell us, and why families should look beyond a headline before making decisions about sleep support.

What did the melatonin study find?

The research was presented at the American Heart Association's 2025 Scientific Sessions. Investigators reviewed five years of electronic health records from 130,828 adults with chronic insomnia. The average participant was 55.7 years old.

• Long-term use was defined as melatonin recorded in the medical record for at least 12 months.
• Heart failure was recorded in 4.6% of long-term users and 2.7% of matched non-users over five years.
• That represents about a 90% higher relative likelihood of a heart failure diagnosis in the melatonin group.

Those numbers deserve attention, but they need to be interpreted carefully.

What the study does not prove

This was an observational analysis, not a randomized clinical trial. It found an association, but it cannot show that melatonin caused heart failure or any other outcome. The findings were presented as a research abstract and had not yet been published as a full, peer-reviewed manuscript.

The study also had important limitations. Over-the-counter melatonin use may not appear in medical records, the researchers did not have complete information about the severity of each person's insomnia, and factors such as anxiety, depression, other medications, or underlying health concerns could have influenced both melatonin use and cardiovascular risk.

What should parents take away?

The participants were adults with chronic insomnia, not children. This study therefore does not provide direct evidence that melatonin causes heart problems in children. It does reinforce a sensible principle: a sleep supplement should not become a long-term substitute for understanding why healthy sleep is difficult.

If your child or another family member uses melatonin regularly, do not start, stop, or change it based only on a headline. Discuss the dose, timing, duration, other medications, and the reason it is being used with an appropriately licensed healthcare professional.

Questions worth asking about sleep

• Is the sleep schedule consistent from day to day?
• Could evening light, screens, stress, or stimulants be delaying sleep?
• Are snoring, breathing changes, restless sleep, pain, or other symptoms present?
• Has the need for ongoing melatonin been reviewed with a qualified healthcare professional?

The bottom line

This study raises an important safety question, but it does not establish cause and effect. The most useful next step is not fear. It is an informed conversation about the reasons behind persistent sleep difficulty and the safest way to address them.

Source: American Heart Association: Long-term use of melatonin supplements may have negative health effects

This article is for educational purposes only and is not a substitute for individualized medical advice, diagnosis, or treatment.