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The hormone melatonin was discovered by an American dermatologist in 1958. He was the first to describe its sleep-promoting effect. In the pea-sized pineal gland (epiphysis), the sleep hormone melatonin is converted from serotonin and is of the utmost importance for a healthy day-night rhythm. However, this conversion is blocked during the day by light in a brain nucleus located above the junction of our optic nerves. If at nightfall this blockade