Side effects of melatonin
Pro Research Analysisby 
Searched over 200M research papers
Side Effects of Melatonin: A Comprehensive Review
Common Side Effects of Melatonin
Melatonin, a hormone produced by the pineal gland, is widely used as a sleep aid and for other therapeutic purposes. Despite its popularity, it is essential to understand the potential side effects associated with its use. The most frequently reported side effects of melatonin include daytime sleepiness, headache, dizziness, and hypothermia. These side effects are generally mild and tend to resolve spontaneously without the need for medical intervention 12.
Serious Adverse Events and Overdose
While most side effects of melatonin are minor, there have been reports of more serious adverse events, although these are rare. Serious side effects can include agitation, fatigue, mood swings, nightmares, skin irritation, and palpitations. These events are typically not life-threatening and often resolve upon discontinuation of the supplement . In cases of overdose, symptoms such as drowsiness, dizziness, fatigue, headache, confusion, nightmares, hypotension, tachycardia, and hypothermia have been observed. Supportive measures and monitoring of vital signs are crucial for managing overdose cases .
Long-Term Use and Special Populations
The long-term safety of melatonin remains less well-documented. Concerns have been raised about its use in specific populations, such as pre-adolescent children and patients with epilepsy or asthma, due to the lack of robust long-term data . Additionally, melatonin's interaction with other medications, particularly those affecting cardiovascular and endocrine functions, necessitates caution. For instance, melatonin can influence blood pressure and glucose metabolism, which may interact with antihypertensive drugs .
Melatonin in Combination Therapies
Melatonin has also been studied for its potential to mitigate side effects of other treatments. For example, in patients with first-episode schizophrenia treated with olanzapine, melatonin was found to reduce weight gain, abdominal obesity, and hypertriglyceridemia, without serious adverse events . Similarly, melatonin has shown neuroprotective effects in patients undergoing chemotherapy, improving cognitive function, sleep quality, and reducing depressive symptoms .
Impact on Sleep and Withdrawal Effects
Melatonin is primarily used to improve sleep quality. Studies have shown that prolonged-release melatonin can significantly enhance sleep quality and morning alertness in older adults without causing withdrawal symptoms upon discontinuation . However, its effectiveness in aiding benzodiazepine discontinuation and improving sleep quality in this context has been inconsistent .
Neuroprotective and Antioxidant Properties
Beyond its role in sleep regulation, melatonin exhibits neuroprotective and antioxidant properties. It has been shown to protect against oxidative stress and improve antioxidant enzyme levels in the hippocampus and prefrontal cortex, which are crucial for cognitive functions . These properties make melatonin a valuable adjunct in treatments that involve oxidative stress, such as chemotherapy .
Conclusion
Melatonin is generally considered safe and well-tolerated, with most side effects being mild and transient. However, caution is advised for long-term use and in specific populations due to the lack of extensive long-term safety data. Its potential interactions with other medications and its role in combination therapies highlight the need for further research to fully understand its safety profile.
Sources and full results
Most relevant research papers on this topic