When someone has advanced sleep phase disorder their melatonin levels and core body temperature will cycle hours earlier than an average person.

The two other groups were never able to bring their melatonin levels into sync with their new schedules, and experienced sleep problems.

They note that morning types evidence a more rapid decline in melatonin levels after the peak than do evening types.

Increased brain serotonin and melatonin levels result in sleepiness.

Natural melatonin production is partly affected by light, since melatonin levels are higher at night than during the day.

If it works, I can suppress some of the serotonin production without changing the melatonin levels.

Earlier studies have reported low melatonin levels among some groups of depressed patients.

It's use is for people whose melatonin level is low due to old age.

Typically, melatonin levels rise in response to darkness (at night) and dip during the daylight hours.

But other studies show melatonin levels stayed the same as people aged.