Your body makes it naturally and usually makes enough. But you can try a supplement of 1 to 3 milligrams 2 hours before bedtime after a sleepless night. It doesn’t make you sleepy, but can have a calming effect that can lead to sleep. Don’t take it if you’re pregnant or breastfeeding. Also stay away if you have seizures, an autoimmune disease, or depression. If you have diabetes or high blood pressure, talk to your doctor before you take it.