Thinking of taking melatonin to help you sleep? Here's what you need to know

Melatonin is a hormone produced by the brain to regulate the sleep-wake cycle. It signals the body to feel sleepy when it's dark. Supplements containing synthetic melatonin can be taken to aid sleep, but not all sleep issues are helped by them. The hormone works by reducing neuron activity in the brain's hypothalamus, the master biological clock.

Melatonin production can be affected by extreme latitudes: in high or low latitudes, the sun may not set or rise, causing problems with melatonin release and consequently, sleep. Age-related decreases in natural melatonin production can also impact sleep.

There are two conditions where melatonin supplements are proven effective: jet lag and difficulty sleeping during the day due to shift work. Melatonin can shorten sleep duration after a night shift and improve sleep, but it doesn't enhance other sleep-related aspects like alertness and fatigue. However, it's generally not effective for chronic insomnia or dementia-related sleep problems.

Melatonin comes in various doses and formulations, with controlled-release tablets over-the-counter for over 55-year-olds with sleep problems. Immediate-release tablets containing up to 5 mg are also available for jet lag. Side effects are usually minor, like daytime sleepiness, headaches, nausea, and dizziness. However, long-term effects are unclear, and high doses may cause weight loss in certain conditions. For better sleep, regular sleep schedules and minimizing evening light exposure are recommended.