Melatonin & Heart Health – The Risks

The popular sleep aid is under scrutiny following a large observational study linking chronic use to an elevated risk of heart failure and mortality.

Melatonin has long been regarded as a safe, “natural” supplement for sleep regulation. However, new data presented at the American Heart Association’s (AHA) Scientific Sessions 2025 has prompted health experts to urge caution, particularly regarding long-term, nightly use. 

The study was a research abstract. Abstracts presented at American Heart Association’s scientific meetings are not peer-reviewed, and the findings are considered preliminary until published as full manuscripts in a peer-reviewed scientific journal.

💔 The Key Finding: An Unforeseen Association

A large, multinational observational study—analyzing the health records of tens of thousands of adults with chronic insomnia over five years—found a significant correlation between long-term melatonin use and serious cardiovascular outcomes.

The most striking statistics were:

• Heart Failure Risk: Individuals whose health records indicated using melatonin for 12 months or more had an approximately 90% higher chance of being diagnosed with incident heart failure over the five-year period, compared to non-users with insomnia.
• Hospitalization & Mortality: Long-term users were also nearly 3.5 times more likely to be hospitalized for heart failure and almost twice as likely to die from any cause during the follow-up period.

🤔 Why the Concern?

The findings are particularly concerning because melatonin is widely available over-the-counter and is often used without medical supervision. While previous research has suggested melatonin may offer cardioprotective benefits due to its antioxidant properties, the long-term safety profile has remained largely unstudied.

The research raises a critical question: is this risk due to the melatonin itself, or is it a reflection of more severe underlying health issues in the chronic users?

IMPORTANT CAVEAT: Researchers emphasize that this was an observational study, meaning it shows an association, not a direct cause-and-effect relationship. It is possible that individuals requiring long-term melatonin use for severe insomnia may also have undiagnosed or more complex cardiovascular risk factors (like severe, untreated sleep apnea, or underlying mental health conditions) that contribute to heart failure, independent of the supplement.

✅ What This Means for You

Experts stress that occasional or short-term use of low-dose melatonin (e.g., for jet lag or temporary sleep schedule adjustments) is generally still considered safe.

However, if you are using the supplement regularly, the new findings recommend a review of this practice:

• Consult Your Healthcare Provider: If you have been taking melatonin nightly for more than one year, especially if you have existing heart disease, high blood pressure, or other cardiovascular risk factors, speak with your doctor or cardiologist.
• Prioritize Behavioral Therapy: For chronic insomnia, health organizations like the American Academy of Sleep Medicine continue to recommend Cognitive Behavioral Therapy for Insomnia (CBT-I) and better sleep hygiene practices as the first-line and most effective treatments.
• “Natural” Does Not Mean “Risk-Free”: This study serves as a crucial reminder that supplements are not subject to the same strict regulation as prescription drugs, and long-term use of any substance should always be discussed with a medical professional.

🔬Evidence-based alternatives to melatonin for managing chronic insomnia

🧠 Cognitive Behavioral Therapy for Insomnia (CBT-I)

CBT-I is a structured, multi-component program that targets the thoughts and behaviors that prevent you from sleeping well. It is often more effective than medication or supplements in the long term.

Key techniques used in CBT-I include:

• Sleep Restriction Therapy: Temporarily limiting time spent in bed to the actual hours you spend sleeping. This creates mild sleep deprivation, leading to deeper, more consolidated sleep when you are in bed.
• Stimulus Control Therapy: Establishing a strong mental association between your bed and sleep by instructing you to only use the bed for sleep and sex, and to get out of bed if you cannot fall asleep after about 20 minutes.
• Cognitive Restructuring: Identifying and changing negative or anxious thoughts about sleep (e.g., “I’ll never sleep well”) into more realistic and positive thoughts.
• Sleep Hygiene Education: Reviewing and optimizing your lifestyle and environment (see below).

🧘 Behavioral and Lifestyle Changes

These are foundational elements for improving sleep quality and are essential components of CBT-I:

• Establish a Consistent Sleep Schedule: Go to bed and wake up at the same time every day, even on weekends. This helps regulate your body’s circadian rhythm.
• Optimize the Sleep Environment: Ensure your bedroom is dark, quiet, and cool.
• Limit Screen Time: Avoid blue light exposure from phones, tablets, and computers for at least an hour before bedtime, as blue light suppresses melatonin production.
• Manage Diet and Substances: Avoid heavy meals, caffeine, and alcohol close to bedtime. While alcohol may initially cause drowsiness, it severely disrupts the second half of the sleep cycle.
• Regular Exercise: Engage in regular physical activity, but try to avoid intense workouts close to your bedtime.

🌱 Herbal and Nutritional Alternatives

While scientific evidence for these is generally less robust than for CBT-I, some people find the following supplements helpful:

• Valerian Root: This herb is one of the most commonly studied herbal sleep aids. Some studies suggest it may help improve sleep quality, though the mechanism is not fully clear.
• Magnesium: Supplementing with magnesium may help improve sleep, especially in older adults with low magnesium levels. It plays a role in relaxing muscles and calming the nervous system.
• L-Theanine: An amino acid found in green tea, L-Theanine doesn’t typically cause sedation but promotes relaxation and reduces anxiety, which can make it easier to fall asleep.
• Other: I can provide you with various solutions based on your personal profile and situation. Beware of off-the-shelf supplements. 

It is highly recommended that anyone dealing with chronic insomnia consult a healthcare provider or a sleep specialist trained in CBT-I, as addressing the underlying causes is the most effective long-term solution.