Daijiworld Media Network - Mumbai
Mumbai, Jan 29: Melatonin supplements, widely used to tackle insomnia and irregular sleep cycles, may not be as harmless as many believe, with new research raising concerns over prolonged use.
Melatonin is a naturally occurring hormone produced by the pineal gland in the brain and plays a key role in regulating the body’s circadian rhythm — the internal clock that controls sleep and wake cycles. While melatonin levels typically rise at night to promote sleepiness and drop in the morning with light exposure, supplements are often taken to manage insomnia, jet lag and shift-work sleep disruptions.
However, experts warn that long-term dependency on melatonin may lead to adverse effects.
A large-scale study presented at the American Heart Association’s (AHA) Scientific Sessions 2025 reported a strong association between extended melatonin use and an increased risk of heart failure.
Researchers analysed five years of electronic health records of over 1.3 lakh adults diagnosed with chronic insomnia. The findings showed that individuals who used melatonin for one year or longer faced:
• 90% higher risk of developing heart failure compared to non-users
• 3.5 times greater chances of hospitalisation due to heart failure
• Double the risk of all-cause mortality over the five-year period
While the study raises major safety questions, medical experts clarified that the findings indicate a correlation and not a direct cause-and-effect link.
Other potential health risks of long-term melatonin use
Though melatonin is generally considered safe for short-term use, prolonged or excessive intake can trigger side effects such as:
Daytime drowsiness: Some users report next-day grogginess or fatigue.
Hormonal changes: Since melatonin is a hormone, it may influence menstrual cycles or cause hormonal imbalance.
Mood fluctuations: Some individuals experience anxiety, irritability or depressive feelings.
Drug interactions: Melatonin may interfere with medications including blood thinners, immunosuppressants and contraceptives.
Tolerance build-up: Long-term use may reduce effectiveness, leading users to increase dosage.
Withdrawal symptoms: Stopping suddenly after extended use can cause rebound insomnia and sleep difficulty.
Impact on growth in children: Experts advise caution for children and adolescents due to possible effects on puberty and development.
Dr Parinita Kaur, Principal Consultant & Unit Head - Internal Medicine at Max Super Speciality Hospital, Dwarka, cautioned that melatonin is often wrongly assumed to be completely safe.
“People assume melatonin is totally safe, but it can cause odd reactions. Some wake up feeling heavy or slow, like they didn’t get proper rest. Others get mild headaches, stomach unsettled, or dreams that feel too real. It can interfere with medicines too, especially things for blood pressure, sugar, or thinning the blood. Those with hormonal issues sometimes feel more sensitive to it. Most side effects show up when someone takes more than they need or keeps using it for too long. Each person reacts differently, so it’s not predictable,” she said.
Health experts advise consulting a doctor before taking melatonin regularly, especially for long-term use, and stress that addressing sleep hygiene and lifestyle habits remains the safest first step for managing insomnia.