Melatonin's Dual Status: Prescription in Israel, Over-the-Counter in US

A recent study has reignited discussions surrounding melatonin, a hormone naturally produced by the body that regulates sleep-wake cycles. While melatonin is widely available as a dietary supplement in the United States, it is a prescription-only medication in Israel, prompting questions about its regulation and use.

Professor Moti Haimi, a regional pediatrician, explained that melatonin's primary function is to signal the body that it is nighttime, thereby adjusting biological clocks. It is not a sedative like benzodiazepines but can aid in conditions like jet lag, delayed sleep phase syndrome, and insomnia in children with autism spectrum disorder. For individuals over 55 with chronic insomnia, it may slightly shorten the time it takes to fall asleep, by about 10 minutes, but it's not typically considered a primary insomnia treatment.

The hormone's efficacy for general anxiety, chronic pain, or immune support remains unproven. A meta-analysis of 28 studies involving over 2,000 individuals with chronic pain found that melatonin offered a modest reduction in pain, averaging 9 points on a 100-point scale, which falls short of the clinically significant 11-14 point improvement. However, it did show a more notable improvement in sleep quality, by an average of 11.35 points.

Melatonin is generally recommended for individuals over 55 with primary insomnia, those with disrupted biological clocks, or frequent travelers. However, it should not be used as a substitute for diagnosing and treating underlying causes of sleep disturbances, such as sleep apnea, anxiety, or pain. Caution is advised for pregnant and breastfeeding women, individuals with autoimmune diseases, epilepsy, or liver conditions. Children should only receive melatonin under medical supervision.

Potential side effects include headaches, dizziness, nausea, and morning drowsiness, with some users reporting vivid dreams. While dependence is not observed, data on long-term use is limited, and it is generally prescribed for short periods in Israel. Interactions with certain medications, like the antidepressant fluvoxamine, are possible, and users should inform their doctors about all medications, caffeine intake, and smoking habits.

In Israel, the prescription drug Cirkadin (2mg prolonged-release melatonin) is approved for short-term insomnia treatment in those over 55, not for pain. The article cautions against relying on foreign-ordered supplements due to potential discrepancies in dosage and unknown long-term safety, citing one study linking prolonged use to an increased risk of heart failure, hospitalization, and death, though causality was not definitively established.