American Heritage® Dictionary of the English Language, Fourth Edition
- n. A hormone derived from serotonin and produced by the pineal gland that stimulates color change in the epidermis of amphibians and reptiles and plays a role in sleep, aging, and reproduction in mammals.
- n. A hormone, related to serotonin, that is secreted by the pineal gland, and stimulates colour change in the skin of reptiles, and is involved in the sleep/wake and reproductive cycles in mammals
- n. Any material similar in its chemistry and effect to the natural hormone.
GNU Webster's 1913
- n. (Physiology) A hormone secreted by the pineal gland. Chemically it is N-acety-5-methoxytryptamine. Research has indicated that there are daily rhythms in secretion of melatonin, in particular due to the depressing effect on melatonin production by light received by the retina. Conversely it appears that melatonin may influence the circadian rhythms of animals. There is some experimental evidence that administration of melatonin may increase the amount of sleep in people with sleep disorders. However, the evidence is not convincing and the effect is not profound. Nevertheless, the deregulation of melatonin and its availability over-the-counter has led to many people taking melatonin to help sleep, without consulting a physician.
- n. hormone secreted by the pineal gland
- Greek melās, black + ton(e) + -in. (American Heritage® Dictionary of the English Language, Fourth Edition)
“Now, you probably also know the word melatonin because in supplement form it’s often used as a sleep aid, and for good reason.”
“This article on sleep and melatonin is also available at Dr. Breus's official blog, The Insomnia Blog.”
“Many supplement companies and health food stores will claim that melatonin is a natural sleeping aid or nightcap because it "naturally" helps regulate sleep-wake cycles.”
“For the record, melatonin is a hormone, and it's not a regulated drug under the FDA.”
“In some parts of Europe, melatonin is available by prescription only.”
“The agency found evidence that melatonin is effective in treating people who have delayed sleep syndrome, who chronically tend to fall asleep well after midnight.”
“Doctors also worry that because melatonin is sold as a supplement, its manufacturing is not as stringently regulated by the Food and Drug Administration as if it were a prescription drug.”
“It's taken from cows once a week at the break of dawn, as they discharge a lot of a stress-relieving hormone called melatonin during the night.”
“Your body actually produces a hormone known as melatonin, and this is a hormone that seems to be produced mainly at night.”
“Blocking that light for five days upset the students 'internal body clocks - delaying by half an hour their evening surge of a hormone called melatonin that helps induce sleep, Rensselaer Polytechnic Institute researchers reported Tuesday.”
These user-created lists contain the word ‘melatonin’.
A list of human hormones
Looking for tweets for melatonin.