insomnia
"I am a 66 year old woman and have been taking Melatonin since 1990's.  I started taking it for sleep  since I had to get up early. There was never any side effects. I started out with 3 mg. Then went up from there. I always knew my limited because to much was creating just the opposite  effects. I am now at 6 mg. and am doing fine.  As we get older the meletonin that our bodies create, diminishes.  Also, sleeping without a light or having a very faint night lite, is best. When getting up to go to the bathroom, do not turn on lights for lights depletes the meletonin in your body. I use a colored night light.  And may I suggest just turning off your computers and phones so they won't interrupt your sleep."