If your pineal gland does not produce adequate melatonin early enough in the evening, it is difficult to go to sleep. If secretion does not continue, you may wake up too soon. If your pineal gland secretes too much or for too long into the next day, you will have a tendency to be sleepy and not rested the next morning. Continuing melatonin production into the day can also result in depression and tiredness. If you do not get adequate sleep, mental acuity decreases, too.
Insomnia exists when melatonin levels are low or when it is produced at the wrong time.
Supplementing can help re-establish balance and help you set your biological clock. Low melatonin levels are associated with lessened thymus activity, steroids metabolism and depression. Much of the activity of the immune system takes place at night and it is thought that melatonin interacts with our immune system during sleep. Melatonin may be an anti-stress factor and its normal rhythmic release is a buffering device, quenching the adverse effects of stress on the immune system. Some researchers believe the steady increase in the incidence of cancer is partially because of the extended time we are exposed to artificial lighting.