Cardiologist with 30 years of experience explains how prolonged and high dose melatonin use impacts the heart
Melatonin supplements are far from harmless. Dr Menon discusses the impact of prolonged, high dose use on heart and cardiovascular health.
For many people, popping a melatonin gummy has become a go-to solution for restless nights, late workdays or disrupted sleep schedules. Marketed as a ‘natural’ and seemingly harmless sleep aid, melatonin is often taken without much thought about dosage or duration. However, medical experts caution that frequent, unsupervised use - especially at higher doses - may not be as benign as it appears. When used long-term or without guidance, melatonin can have subtle yet significant effects on the heart and cardiovascular system, making medical advice essential before turning it into a nightly habit.
Dr Ajit Menon, Director of Cardiac Sciences at Sir H.N. Reliance Foundation Hospital, Mumbai, and an interventional cardiologist with over 30 years of experience, spoke to HT Lifestyle about the effects of unregulated and prolonged melatonin use on heart and cardiovascular health.
What is melatonin?
According to Dr Menon, melatonin is a naturally occurring hormone secreted by the pituitary gland, which plays a key role in regulating the body’s sleep-wake cycle. He states, “In clinical practice, melatonin is often prescribed to manage short-term sleep disturbances, especially in situations such as jet lag, long work shift disruptions, or transient insomnia. When used under medical supervision, in low doses ranging from 0.5 mg to 2 mg, and for short durations, melatonin is generally considered safe and largely neutral in terms of heart health.”
When does it become a problem?
The cardiologist notes that while melatonin is generally considered safe in low doses and under medical supervision, concerns arise when it is self-prescribed and taken in high doses over extended periods. He highlights, “However, concerns arise when melatonin is self-prescribed, especially in higher doses, or used for long periods without medical oversight - a worrying trend that has become increasingly common due to its ease of over-the-counter availability.”
Effects on cardiovascular system
Dr Menon highlights that melatonin can have physiological effects on the heart, including lowering blood pressure and heart rate. While these changes may be insignificant in healthy individuals, they can pose concerns for those with underlying heart conditions.
He explains, “It can lower blood pressure and heart rate, which may not be problematic in healthy individuals but can become concerning in people with underlying coronary artery disease, rhythm disorders, or other cardiac conditions. In such patients, these effects may lead to dizziness, fatigue, or even worsening of existing heart issues.”
Drug interactions
The cardiologist points out that melatonin may interact with prescribed blood pressure medications as well as blood thinners, as it already lowers blood pressure, making potential drug interactions a significant concern.
He explains, “This could increase the effect of these medications and thus result in a greater than normal drop in blood pressure. Melatonin may also have an interaction with certain blood thinners, thus increasing the risk of an internal bleed. This possibility is often unknown to people when self-medicating.”
Effects on the elderly
Dr Menon highlights that older adults are particularly vulnerable to the effects of melatonin, as they may already be frail or at higher risk. When combined with melatonin’s blood-pressure-lowering effects, this can increase the likelihood of falls, fractures and related accidents.
He elaborates further, “In this population, melatonin may act to promote autonomic dysfunction, resulting in a significant drop in blood pressure when changing position from a sitting or lying down position to a standing position. This gradual drop in blood pressure places this population at increased risk of falls, fractures, and related accidents, which can be quite serious for older adults.”
Widespread availability is concerning
One of the main concerns of cardiologists, according to Dr Menon, is the widespread availability of high-dose melatonin products - ranging from five to 10 milligrams - which can even be purchased without a prescription. He cautions against unregulated and prolonged use of melatonin products, since higher doses used over longer durations increases the possibility of experiencing side effects. The cardiologist adds, “Unregulated use of high-dose melatonin can also lead to drowsiness during the day, thus affecting a person's ability to work, perform, and operate a vehicle or machinery.”
Melatonin can be a useful aid for sleep when used correctly, but it is not a harmless supplement. Dr Menon concludes, “Individuals with heart disease, those on blood pressure medications or blood thinners, and older adults should be cautious. Melatonin should ideally be taken only after medical consultation, at the lowest effective dosage, and for the shortest duration necessary to ensure both sleep benefit, and cardiovascular safety.”
Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.
