Melatonin and Heart Failure: Should You Be Worried About the Latest Study?

Sleep difficulties are among the most common complaints in our practice. Many people turn to the over-the-counter hormone supplement Melatonin thinking it’s harmless because “it’s natural.” Yet very recently a large scale observational study raised questions about the safety of long-term use. Let’s step through what the study found, what it didn’t find, how it applies (or doesn’t) to you, and what smart alternatives may be.

What the new study found

• A multinational data analysis tracked over 130,000 adults diagnosed with insomnia.
• Among those who had been prescribed melatonin and used it at least one year, the risk of a heart-failure diagnosis was 90% higher compared to matched non-melatonin users.
• They also observed higher hospitalization rates for heart failure and increased all-cause mortality in the melatonin group.
• However: the study is observational — it cannot prove that melatonin caused the higher risks.

What the study did not settle

• The dosage of melatonin used by patients was not clearly documented in the health-record data.
• Over-the-counter usage may not have been captured (the “non-user” group could include people taking melatonin but without prescription).
• It may be that worse insomnia, anxiety/depression, or other sleep-aid use (rather than melatonin itself) were driving the increased risk.
• The study focused on long-term use (at least one year) among a specific cohort; it doesn’t apply directly to short-term, occasional use.

How to interpret this for you

• If you are using melatonin very occasionally (for jet-lag, shift work, or a short-term sleep disruption), the existing evidence still supports that melatonin can help with sleep onset.
• If you are using melatonin nightly for months or years without consulting a sleep specialist or addressing the root cause of your insomnia, this study suggests you may want to reevaluate.
• Because the supplement industry is less strictly regulated, dosages of melatonin products vary widely (some contain far more or far less than the label says).
• Most importantly: don’t stop any supplement abruptly—talk with your physician, especially if you have heart disease or other risk factors.

Smart sleep-aid alternatives & practical tips

• Try behavioural changes first: consistent sleep schedule, limiting blue light before bed, relaxing routine, cool/dark/quiet environment.
• See a sleep specialist if insomnia persists — treatments such as cognitive behavioural therapy for insomnia (CBT-I) are highly effective.
• If you do use melatonin, use the lowest dose that is effective, use it only when needed, and monitor with your provider.
• Make sure the product you choose is third-party tested (look for USP or NSF mark).

Conclusion‍

The recent study raises a significant red-flag about long-term, nightly melatonin use — but it doesn’t mean melatonin is “unsafe for everyone.” It does mean we need to be thoughtful, informed, and monitored. At BASS Medical Group, we encourage meaningful conversation about sleep aids, root-cause sleep health, and tailored strategies—not one-size-fits-all supplements.

FAQs

Q1: Is melatonin completely unsafe now because of this study?

A1: No. This study shows an association between long-term melatonin use and higher risk of heart failure—but does not prove causation. If you take melatonin occasionally and have no significant heart/failure risk factors, it may still be a reasonable option. But if you’re taking it nightly for a year or more, or have heart disease, you should talk to your provider.

Q2: How much melatonin should I take and for how long?

A2: There is no “one correct” dosage for everyone. Studies and guidelines suggest using the lowest effective dose, for the shortest needed duration, and in the context of good sleep hygiene. Because product dosages vary widely and aren’t uniformly regulated, it is wise to select a third-party-tested product, take under physician guidance, and use it as part of a larger sleep-health strategy.