Melatonin has always been a popular Hormone that has been studied. It is known to play a role in our sleep-wake cycles. However, as we've seen recently, it slows down premature aging and acts as a neurological guardian.

Cone glands produce melatonin or N-acetyl-5-methoxy tryptamine from tryptophan. The correct melatonin level allows us to sleep and synchronize our neurotransmitters.
Deficiency of this hormone not only causes insomnia, it also impairs many cognitive functions such as attention and memory. It even poses a high risk for neurological degenerative diseases.