PolskiPreliminary data from the American Heart Association (AHA) suggest that in adults with chronic insomnia, long-term (≥12 months) melatonin use was associated with a 90% higher risk of developing heart failure – 4.6% vs. 2.7% over 5 years. This is an observational analysis, announced at a conference (not in a peer-reviewed journal), so it does not prove causation and needs to be confirmed in further studies. What does this mean for you? If you are reaching for melatonin regularly and especially having heart disease, high blood pressure or taking multiple medications then talk to your doctor. And if you’re struggling with insomnia, consider a method with proven efficacy without pharmacological risks.
Table of Contents:
- Melatonin and the heart: what do we really know?
- Study says “relationship,” not “cause”
- Percentages in surveys don’t tell the whole truth – how to read risk, why numbers alone are misleading
- Who should exercise caution when taking melatonin
- Melatonin: supplement or drug – what is the difference
- Supplement to supplement unequal – quality matters, how to choose melatonin without disappointment
- Not getting enough sleep? Start with pill-free methods – CBT-I and sleep hygiene instead of shortcuts
- When it’s better to call a doctor than Google – signals that it’s time for a consultation
- How to wisely reduce or wean off melatonin – safe step-by-step changes
- Practical tips for women – what to do tonight to sleep better
Melatonin and the heart: what we really know
A preliminary study (abstract MP2306) from the American Heart Association (AHA) has caused considerable concern, suggesting that chronic melatonin use (for at least 12 months) may be linked to a nearly twofold increase in heart failure risk. Researchers analyzed five years of health data from more than 130,000 adult patients previously diagnosed with insomnia. The result, also reported by media outlets such as People, is a wake-up call for the millions of users of this popular sleep aid.
Study says “relationship,” not “cause”
A key caveat, experts point out, is that the study is observational. This means that the researchers observed an association or correlation between long-term melatonin use and heart failure, but did not prove causality – that is, that melatonin directly causes the disease.
Many cardiologists believe that melatonin may be a marker for a more serious problem: chronic insomnia, which requires long-term treatment, is itself a strong and independent cardiovascular risk factor. Poor sleep contributes to hypertension, inflammation and chronic stress, which ultimately lead to heart failure. Therefore, the need for melatonin as a support may mask underlying cardiac problems.
Percentages in surveys don’t tell the whole truth – how to read risk, why numbers alone are misleading
The value of having a 90% higher risk is statistically correct, but can be misleading. It refers to relative risk, which sounds dramatic but does not reflect the magnitude of the problem in the general population.
4.6% vs 2.7% at 5 years in people with insomnia
In the AHA study, absolute risks were distributed as follows:
- Control group (without melatonin): 2.7% developed heart failure within 5 years.
- Melatonin group (long-term use): 4.6% developed heart failure within 5 years.
The relative risk has increased by 90% (almost doubling), but the absolute risk for the average healthy user is still low. This difference is key: it is not a 90% risk of getting sick, but a 90% increase in the likelihood of getting sick relative to people with insomnia who do not use melatonin.
Who should exercise caution when taking melatonin
While the results should not cause panic, they do indicate the need for special caution in several groups of patients:
- People with existing heart disease (e.g., heart failure, coronary artery disease).
- Patients with hypertension or other cardiovascular risk factors.
- People taking multiple cardiovascular or anticoagulant medications – melatonin can interact by altering their metabolism.
- People using melatonin long-term (more than 12 months) and/or in high doses (more than 5 mg).
Melatonin: supplement or drug – what is the difference
The legal status of melatonin has a direct impact on its safety and is one of the reasons why caution is advised.
| Melatonin in Europe: Regulatory Status |
| Poland/EU: Melatonin is available as a dietary supplement (without drug standardization) and as a prescription drug. |
| Circadin (2 mg): This is an EU-approved drug for the short-term treatment of primary insomnia in patients aged 55 and older. The maximum recommended duration of therapy is about 13 weeks. |
| United Kingdom (UK): Melatonin is also a prescription drug. |
The use of melatonin as a dietary supplement without medical supervision, especially over long years, can lead to the accumulation of unknown side effects.
Supplement to supplement unequal – quality matters, how to choose melatonin without disappointment
The lack of rigorous control over dietary supplements leads to a problem that can indirectly increase health risks: dose instability.
Numerous laboratory analyses have shown that the melatonin content of tablets and jellies often differs drastically from that declared on the label:
- The study showed that the actual melatonin content of the supplements ranged from -83% to +478% compared to what appeared on the package.
- Even within the same brand, differences in concentration between batches of product reached 465%.
- In the case of popular jellybeans (gummies), it was found that the actual dose in the product was even several times higher than the declared one.
This means that a patient taking “3 mg” of melatonin may actually be unknowingly taking doses on the order of 10-15 mg, a pharmacological dose with unpredictable long-term cardiovascular effects.
Not getting enough sleep? Start with pill-free methods – CBT-I and sleep hygiene instead of shortcuts
For those struggling with chronic insomnia, the American Academy of Sleep Medicine (AASM) has maintained for years that Cognitive Behavioral Therapy for Insomnia (CBT-I) is the treatment of first choice (the so-called gold standard).
CBT-I is a short-term, structured therapy that eliminates the need for ongoing pharmacotherapy by teaching the brain how to fall asleep independently and effectively. It has proven long-term effectiveness and is free of the risks associated with the use of drugs or supplements.
When it’s better to call a doctor than Google – signals that it’s time for a consultation
is the best time to be proactive:
- If you have been using melatonin for more than 3 months.
- If your insomnia requires increasingly higher doses.
- If you have a diagnosis of hypertension, arrhythmia or other heart disease.
- If you are planning a pregnancy, breastfeeding or have safety concerns.
How to wisely reduce or wean off melatonin – safe step-by-step changes
Never stop taking melatonin suddenly, especially if you have been taking it for a long time. Abrupt withdrawal can cause what is known as reboundinsomnia, a sudden, severe increase in sleep problems that is a stressor to the heart. Any changes should be supervised by a doctor and should go hand in hand with starting CBT-I therapy or improving sleep hygiene.
Practical tips for women – What to do tonight to sleep better
Focusing on sleep hygiene is a safe and effective way to improve the quality of nighttime rest:
- Consistent rhythm: Lie down and get up at the same time (including weekends).
- Dark and cool: Make sure the bedroom is quiet, dark and cool.
- Digital detox: Avoid phones, tablets and laptops a minimum of 60 minutes before bedtime (blue light inhibits natural melatonin production).
- Moderation with stimulants: Avoid caffeine in the afternoon and alcohol in the evening.
Sources in the article:
- American Heart Association press release (MP2306): methodology, numbers (4.6% vs. 2.7%), limitations.
- People.com – coverage with expert comments (secondary material).
- JAMA 2023 – melatonin gummies: discrepancies vs. label.
- J Clin Sleep Med 2017 – Melatonin variability.
- AASM 2017 insomnia pharmacotherapy guidelines (CBT-I as 1st line) + review of CBT-I effectiveness.
- NHS – Rx status in the UK, typical treatment lengths.
- EMA (EU/PL) – Circadin 2 mg: indication and maximum duration of therapy.
