From the Guidelines
Melatonin is generally considered safe for short-term use, but it can cause several side effects, and the benefits of use appear to outweigh any potential harms, as no serious adverse reactions to melatonin have been described to date 1.
Common Side Effects
- Drowsiness
- Headache
- Dizziness
- Nausea Some people may experience vivid dreams or nightmares, irritability, and temporary feelings of depression. Less common side effects include mild tremor, anxiety, abdominal cramps, and reduced alertness.
Important Considerations
Melatonin may also interact with certain medications including blood thinners, immunosuppressants, diabetes medications, and birth control pills, and caution is advised when prescribing to patients taking warfarin and to patients with epilepsy 1. The risk of side effects increases with higher doses, so it's best to start with the lowest effective dose (typically 0.5-3 mg for sleep issues) 1.
Long-term Use and Special Populations
Studies that address long-term effects are scarce, as are studies that specifically involve pediatric/adolescent populations, but a long-term follow-up study of pediatric patients with DSWPD + attention deficit hyperactivity disorder (ADHD) who utilized melatonin doses up to 10 mg detected no serious adverse events 1.
Recommendation
It is recommended to use melatonin with caution, starting with the lowest effective dose, and to consult with a healthcare provider if you experience persistent or severe side effects, as the benefits of use appear to outweigh any potential harms 1.
From the Research
Melatonin Side Effects
- The most frequently reported side effects of melatonin include daytime sleepiness (1.66%), headache (0.74%), other sleep-related side effects (0.74%), dizziness (0.74%), and hypothermia (0.62%) 2.
- Serious or clinically significant side effects are rare, but may include agitation, fatigue, mood swings, nightmares, skin irritation, and palpitations 2.
- Melatonin is generally considered safe and well-tolerated, with most side effects resolving spontaneously or upon withdrawal of treatment 2, 3, 4.
- Long-term use of melatonin may be associated with mild to moderate side effects, but there is limited evidence on its safety over extended periods 2, 4.
- Certain populations, such as pre-adolescent children, patients with epilepsy or asthma, pregnant and breast-feeding women, may be at higher risk of side effects, but more research is needed to confirm this 2, 4.
Comparison with Other Sleep Disorders Treatments
- Melatonin has been shown to have significantly fewer side effects compared to currently available pharmaceutical therapies for sleep disorders, such as benzodiazepines, antidepressants, antihistamines, and anxiolytics 3, 5.
- Melatonergic drugs, such as ramelteon, agomelatin, and tasimelteon, have been developed as alternatives to melatonin and may have similar safety profiles 5.