From the Guidelines
Melatonin is generally considered safe for short-term use, but it can cause side effects including headaches, somnolence, hypotension, hypertension, gastrointestinal upset, and exacerbation of alopecia areata, particularly at higher doses or in individuals with preexisting conditions 1. When considering the use of melatonin, it is essential to weigh the potential benefits against the possible risks. The majority of studies suggest that melatonin is well-tolerated, with few reported serious adverse effects 1. However, some individuals may experience adverse effects such as:
- Headaches
- Somnolence
- Hypotension
- Hypertension
- Gastrointestinal upset
- Exacerbation of alopecia areata It is also important to note that melatonin may interact with certain medications, including blood thinners, and caution is advised when prescribing to patients taking warfarin or to patients with epilepsy 1.
Key Considerations
To minimize the risk of side effects, it is recommended to:
- Take melatonin 30-60 minutes before bedtime
- Use the lowest effective dose (typically 0.5-5mg for adults)
- Avoid long-term use without medical supervision
- Choose a formulation that is United States Pharmacopeial Convention Verified to ensure reliability and purity 1 By following these guidelines and being aware of the potential side effects, individuals can use melatonin safely and effectively to regulate their sleep-wake cycles.
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
Specific Populations
- There is limited evidence on the safety of melatonin in certain populations, such as pre-adolescent children and patients with epilepsy or asthma 2
- Melatonin may be beneficial for children with neurodevelopmental disabilities, particularly in advancing sleep onset 4
Long-term Use
- The scarcity of evidence from long-term randomized controlled trials limits conclusions regarding the safety of continuous melatonin therapy over extended periods 2
- Further studies are needed to assess the safety and efficacy of melatonin for long-term use 2, 5
Comparison to Other Treatments
- Melatonin may offer an alternative treatment to currently available pharmaceutical therapies for sleep disorders, with significantly fewer side effects 3
- Melatonin has been shown to synchronize circadian rhythms, improve sleep onset, duration, and quality, and has anti-oxidation and anti-inflammatory effects 3, 6