Long-term melatonin use may have negative impact on the heart

A recent international study presented at the American Heart Association Scientific Sessions has linked extended melatonin use for insomnia with a higher risk of heart failure, hospitalization due to heart issues, and overall mortality.

“Melatonin supplements may not be as harmless as commonly assumed. If our study is confirmed, this could affect how doctors counsel patients about sleep aids,” said Ekenedilichukwu Nnadi, MD, chief resident in internal medicine at SUNY Downstate/Kings County Primary Care, Brooklyn.

Nnadi pointed out that melatonin is generally seen as a safe and natural solution for sleep problems, making the connection between regular use and severe cardiovascular outcomes especially notable. The research team used data from the TriNetX Global Research Network to analyze 130,828 adults diagnosed with insomnia, with an average age of 56 years and 61% of them being women.

Study findings

Long-term melatonin use correlated with a higher incidence of heart failure.
Patients using melatonin regularly showed greater risk for hospitalization related to heart conditions.
An increase in all-cause mortality was also observed among prolonged users.

The authors emphasize the need for more research to confirm these findings and evaluate the long-term safety of melatonin as an over-the-counter sleep remedy.

Author’s Summary

Prolonged melatonin use for sleep may raise serious heart risks, prompting doctors to reconsider its safety for patients with insomnia.

Healio — 2025-11-07