From the Guidelines
Melatonin 1mg MR is considered safe for long-term use with minimal risks for most adults, but it is essential to be aware of potential interactions and side effects, as evidenced by studies such as 1. The most common side effects are mild and include headache, dizziness, nausea, and daytime drowsiness. Long-term risks appear to be limited, with no evidence of dependency, withdrawal effects, or significant tolerance development. However, some theoretical concerns exist about potential hormonal effects with prolonged use, including possible impacts on reproductive hormones, though clinical evidence for these concerns is limited, as noted in 1. Melatonin may interact with certain medications including blood thinners, immunosuppressants, and some diabetes medications. For optimal use, take melatonin 1-2 hours before bedtime consistently, and practice good sleep hygiene alongside supplementation. While melatonin is available over-the-counter in many countries, it's advisable to periodically reassess your need for it with your healthcare provider, especially if using it beyond a few months, as suggested by 1 and 1. If you have underlying health conditions such as autoimmune disorders, seizure disorders, or depression, consult your doctor before long-term use as melatonin might affect these conditions. Some key points to consider when using melatonin for sleep include:
- Starting with a low dose and gradually increasing as needed
- Being aware of potential interactions with other medications
- Monitoring for side effects and adjusting usage accordingly
- Practicing good sleep hygiene to maximize the effectiveness of melatonin supplementation
- Regularly reviewing the need for continued use with a healthcare provider, especially for long-term use, as recommended by 1 and 1.
From the Research
Long-term Risks of Melatonin 1mg MR for Sleep
- The current evidence on the long-term risks of melatonin 1mg MR for sleep is limited, and most studies have focused on higher doses of melatonin 2, 3, 4, 5.
- A systematic review and meta-analysis of high-dose melatonin (≥10 mg) in adults found that melatonin appeared to have a good safety profile, but the confidence limits were wide due to the paucity of suitable data 2.
- A narrative review of chronic melatonin administration found that melatonin at low to moderate dosages (approximately 5-6 mg daily or less) appears safe, but the long-term effects of taking exogenous melatonin have been insufficiently studied and warrant additional investigation 3.
- A review of the risks of using melatonin as a treatment for sleep disorders in older adults found that melatonin appears to have a favorable safety profile in this population, but there is a dearth of evidence regarding the safety of prolonged use 4.
- A review of adverse events in long-term studies of exogenous melatonin found that the reported frequency of possible adverse events associated with long-term melatonin use is low, but the scarcity of data from double-blind randomized placebo-controlled trials should caution against complacency 5.
Adverse Events Associated with Melatonin Use
- The most common adverse events associated with melatonin use are drowsiness, headache, and dizziness 2.
- Other potential adverse events associated with melatonin use include increased risk of bleeding, interactions with other medications, and effects on glucose regulation and blood pressure 3, 4.
- The risk of adverse events may be increased in older adults, particularly those with certain medical conditions or taking certain medications 4.