Can melatonin supplements be dangerous?

Taking melatonin to help you sleep may seem harmless, but new data suggests it may have repercussions on your heart health.

An American Heart Association study reviewed five years’ worth of health records from over 130,000 adults. The study’s participants all had insomnia and had been taking melatonin for at least a year. They found that those who had insomnia and took melatonin for at least a year were more likely to be diagnosed with heart failure, require hospitalization for heart failure or die from other causes.  

“About 50% of people with insomnia also have untreated sleep apnea,” says Dr. Yelena Tumashova, a sleep medicine specialist at Advocate Health Care. “People with untreated sleep apnea tend to overuse over–the–counter (OTC) medications, like melatonin. Therefore, the increased risk of heart disease is more likely connected to one’s untreated sleep apnea rather than one’s use of melatonin.” 

Sleep apnea is a disorder where you experience disrupted breathing during sleep. Common symptoms include snoring, mouth breathing and pauses in breathing while asleep.

Why do people take melatonin supplements? 

Melatonin is a hormone that the body naturally produces, which helps regulate your sleep-wake cycle. Your body releases the hormones when it’s dark out, which helps your body ease into sleep at night. People who struggle with sleep issues, like insomnia, may opt to use melatonin supplements since they mimic the hormone release and promote sleepiness.  

“Taking OTC melatonin tablets isn’t uncommon, especially for people with jet lag and/or insomnia,” says Dr. Tumashova. “Because the supplements are available OTC, they don’t require government approval for consistency, so each brand can vary in strength and purity.” 

How to use melatonin safely 

If you’re going to use melatonin supplements, it’s important to keep a few things in mind: 

• Medication reactions. People with epilepsy or those taking blood thinners may need additional supervision when taking the supplement. 
• Allergic reactions. Just like when taking any medication, it’s important to monitor for symptoms such as developing a rash or experiencing itching or swelling.  
• Safety concerns. Taking melatonin can increase the risk of falls among older people, especially those with dementia. 
• Consistency discrepancies. Products may have varying strengths despite what is listed on the label. 

If you’re experiencing symptoms like headaches, dizziness, nausea or increased sleepiness during daytime hours, reach out to your health care provider to make sure you’re not experiencing something more severe. 

Learn your risk for heart disease by taking this free online quiz.