A hormone that’s made by the pineal gland in the brain, melatonin helps control your daily sleep-wake cycles. Your body’s internal clock (also known as your circadian rhythm) influences how much melatonin the pineal gland makes, and so does the amount of light that you’re exposed to each day. Typically, melatonin levels start to rise in the mid-to-late evening, after the sun has set. They stay elevated for most of the night while you’re in the dark. Then, they drop in the early morning as the sun rises, causing you to awaken.
During the shorter, darker days of winter, your body may produce melatonin earlier or later in the day, which partly throws off your natural sleep cycles. As a result, you may experience fatigue, a drop in energy, mood changes, or other symptoms of seasonal affective disorder. Natural light isn’t the only external factor that influences melatonin levels, though: Foods such as tomatoes, walnuts, olives, rice, barley, strawberries, cherries, and cow’s milk contain melatonin. When your body absorbs melatonin from these foods, you may begin to feel calm and sleepy.
At drugstores and natural-food stores, you can buy melatonin supplements, which are often used by those who suffer from jet lag, shift-work-related sleep troubles, or insomnia. These supplements come in pill, liquid, chewable, or lozenge forms, in doses ranging from one to 10 milligrams. For insomnia, it’s best to take a melatonin supplement 30 to 60 minutes before bedtime. That way, it can put you in the mood to snooze by the time you want to turn out your lights for the night. Keep in mind, though, that melatonin supplements can negatively interact with many different medications, so be sure to check with your doctor before taking the sleep-inducing aid.