The melatonin pathway depends on cycles of light and dark, as its production and secretion are related to light input and optic nerve processes.

Blood melatonin levels range from 0 to 20 pg\ml during daytime and 40-100 pg\ml during night time, reaching a peak between midnight and 3-4PM, when light presence is the lowest.
Inevitably, scientists tried to find out if the melatonin pathway can be used therapeutically, but were disappointed to discover that although light pollution during the night interrupts melatonin secretion, staying in the dark during daytime, there’s no guarantee that melatonin production will be triggered.

Melatonin also plays an important role in sexual maturation, being a crucial link in the chain of production and secretion of testosterone, astrogen and progesterone. Studies performed on primates have shown that increasing amounts of melatonin reflect decreased fertility, though there’s no clear evidence of the same trend among humans. High amounts of melatonin found in correlation with early sexual maturation among youngsters, a piece of information which suggest a very strong connection between good sleeping habits and our health. Last but not least, melatonin was also found as an inhibitor of sex activity levels, standing in correlation with the data regarding fertility. All in all, maintaining melatonin levels seems to be really beneficial.

When we talk about healthy well-being and sleeping habits, melatonin is one of the most important keys on the way to the big prize - feeling good, really good. In addition to its positive effect on sleeping quality, it’s also related to regulation over blood levels of glucose, blood pressure, body temperature and hormonal balance. Recent research even pointed to a connection between melatonin and diabetes, as melatonin takes part in glucose metabolism, contributing to the understanding that melatonin has a strong position regarding our health and well-being.