In response to media coverage of an abstract presented at the American Heart Association’s Scientific Sessions 2025 (see related press release) suggesting an association between long-term melatonin use and increased risk of heart failure, the Council for Responsible Nutrition (CRN) issues the following statement:
CRN urges all stakeholders to interpret these preliminary findings with caution and context. As the American Heart Association itself notes, this research represents early, non–peer-reviewed data that cannot establish cause and effect. Chronic insomnia—a condition shared by all study participants—may itself be a contributing factor to heart health outcomes, raising more questions than answers.
The study population was limited to patients with chronic insomnia, comparing those with documented melatonin use for at least a year to those without such records. As The Washington Post accurately reported (subscription required), quality sleep is critical for cardiovascular health, and individuals who sleep poorly tend to have higher heart rates and blood pressure and experience more cardiovascular events. Therefore, these findings are unlikely to apply to healthy adults who use melatonin dietary supplements occasionally for sleep support.
Melatonin supplements are not intended to treat chronic insomnia or other sleep disorders. CRN’s voluntary melatonin labeling guidelines, adopted in 2024, recommend upper dosage levels and include advisory statements such as “For occasional and/or intermittent use only” and “Consult a healthcare professional if you are experiencing long-term sleep difficulties.”
Additional study limitations include a lack of data on melatonin dose, insomnia severity, psychiatric comorbidities, and potential unrecorded supplement use among control participants—factors that may have distorted the apparent association. As The Washington Post correctly summarized, the results “show association, not causation,” and experts agree that “further research is needed before drawing conclusions.”
Melatonin is a naturally occurring hormone with well-established short-term uses for regulating sleep timing and circadian rhythm. Decades of consumer experience and multiple clinical studies indicate that low-dose, short-term supplementation is safe for healthy adults when used as directed. The observational data presented at AHA do not alter that safety profile.
CRN supports ongoing scientific research to better understand long-term use patterns of all dietary supplements and welcomes rigorous, peer-reviewed investigations that contribute to evidence-based guidance. However, no single study—especially a preliminary abstract—should serve as the basis for broad conclusions or alarmist headlines about dietary supplements.
Consumers who use melatonin should consult their healthcare providers, particularly if they have cardiovascular concerns, before making any changes to their regimen.
As study author Dr. Ekenedilichukwu Nnadi told The Washington Post, “The takeaway isn’t that melatonin is ‘bad’ or that everyone should stop taking it. It’s that we shouldn’t assume something is risk-free just because it’s natural or sold over the counter.” CRN agrees—and encourages thoughtful, evidence-based interpretation rather than overreaction to early findings.
