Endogenous melatonin

Endogenous melatonin has no effect on sleep in humans.

“Correlational analyses comparing sleep in the placebo condition with melatonin production revealed that melatonin levels were not correlated with sleep.”

Humansplacebo condition in patients with age-related sleep-maintenance insomnia

The role of melatonin and circadian phase in age-related sleep-maintenance insomnia: assessment in a clinical trial of melatonin replacement

Sleep·1 Jan 1998