Melatonin Long-Term Use Increases Heart Failure Risk by 90% – Shocking Findings!

A recent study presented at the AHA Scientific Sessions 2025 suggests a compelling connection between long-term melatonin use and an increased risk of heart failure.

90 Percent Higher Risk

This observational study analyzed data from 130,828 adults with chronic insomnia. Researchers compared individuals who had taken melatonin for at least twelve months to a control group without long-term use.

The findings were alarming: long-term melatonin users had a 90% higher risk of developing heart failure. Additionally, hospitalization rates starkly differed—19% in the melatonin group versus 6.6% in the control group. Mortality rates also showcased a disturbing trend: 7.8% compared to 4.3%.

Experts like Prof. Dr. Ferdinand Vogt caution against jumping to conclusions. While the study establishes a correlation, it does not confirm causation. Nonetheless, it’s evident that individuals on prolonged melatonin regimens should do so under medical supervision. Short-term use remains considered safe.

Regulatory Scrutiny Increases

In light of these findings, regulatory bodies worldwide are ramping up efforts to control illegal melatonin products. In June 2026, the Australian TGA imposed fines totaling $99,000 against a pharmaceutical company for the illegal importation of unapproved products.

Authorities are also warning consumers about counterfeit products from unofficial sources, which could pose additional health risks due to contamination or incorrect dosages.

Part of a Larger Trend

The ongoing melatonin debate is part of broader efforts by medical societies. In July 2026, the American Heart Association and the American College of Cardiology released new guidelines regarding the CKM syndrome, outlining the complex interconnections between the heart, kidneys, and metabolism.

With illegal melatonin products flooding the market, the TGA recently imposed fines of $99,000. Our report highlights how to identify contaminated products and offers medically supervised withdrawal options.

In April, the German Society for Internal Medicine updated its recommendations, focusing on exercise therapies to reduce cardiovascular risks. Medical professionals are increasingly advocating for stringent controls over inflammatory processes in medications.

Research published in 2026 in the journal Cardiovascular Research also indicates that inflammation—such as that caused by elevated oxalate levels—can promote kidney and heart damage. These systemic connections explain why the uncritical, long-term use of hormonally active substances like melatonin is coming under increasing scrutiny.