Long-term melatonin use linked to 90% higher heart failure risk

New research presented at a major cardiology conference suggests that people with chronic insomnia who take melatonin long-term may face a roughly 90% higher risk of developing heart failure within five years. While the findings are preliminary and do not prove causation, they inject a sobering note into the growing enthusiasm for melatonin as a “safe” sleep aid. For millions who reach for this supplement night after night, the study underscores an urgent need to revisit its long-term safety profile and consider whether we’ve been too quick to label it harmless. As we await more rigorous data, this is a moment for both patients and clinicians to pause, weigh the evidence, and explore alternative insomnia treatments. As a journalist who has covered the quiet rise of melatonin from obscure hormone to household staple, I found this study both alarming and, frankly, overdue. Melatonin has enjoyed an unearned reputation as the benign answer to restless nights—a natural supplement you can grab alongside vitamins without a second thought. But nature does not automatically equal safety, and this preliminary analysis, reported by ScienceDaily, challenges the complacency that has surrounded this popular sleep aid. The study followed people with chronic insomnia, a population already vulnerable to cardiovascular issues, and found a striking association between long-term melatonin use and heart failure risk over five years. It is crucial to emphasize that correlation is not causation—perhaps those who use melatonin persistently have more severe insomnia, which itself could drive heart strain. But even with that caveat, the signal is strong enough to demand serious investigation. We cannot dismiss a 90% elevated risk as noise, especially when millions of adults use melatonin daily, often without medical supervision. This brings me to a broader concern: the Wild West of dietary supplements. Unlike pharmaceuticals, supplements are not held to the same rigorous pre-market safety and efficacy standards. Melatonin, in particular, is often self-prescribed in doses far exceeding physiological levels, for durations never tested in clinical trials. We have essentially conducted a massive, uncontrolled experiment on the public. This study is a wake-up call that “natural” interventions deserve the same scientific scrutiny we demand of any molecule that alters our biology. For patients with chronic insomnia, the takeaway isn’t to panic or flush your melatonin just yet. It’s to have an honest conversation with your healthcare provider about why you’re using it, how long you’ve been on it, and what alternatives exist. Cognitive behavioral therapy for insomnia (CBT-I) remains a first-line, evidence-based approach with no cardiovascular red flags. And if melatonin is used, it should be at the lowest effective dose, for the shortest duration possible—not as an indefinite nightly ritual. Source: https://www.sciencedaily.com/releases/2026/08/260829035228.htm