organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l -stereoisomer appears in mammalian protein. It is one of several essential amino acids needed in the diet; human beings cannot synthesize it from simpler metabolites. Young adults require about 7 mg of this amino acid per day per kg (3 mg per lb) of body weight. Nicotinic acid (niacin), a vitamin of the B complex, can be made from tryptophan in the body, but evidently the rate of transformation is insufficient for the demands of normal growth and maintenance, and hence nicotinic acid must be supplied in the diet. Deficiency of tryptophan in the diet enhances the progress of the vitamin-deficiency disease pellagra , which is treated by restoring nicotinic acid to the diet, usually supplemented with tryptophan. Bacteria in the intestine break tryptophan down to compounds such as skatole and indole, which to a great extent are responsible for the unpleasant odor of feces. Tryptophan contributes to the structure of proteins into which it has been incorporated by the tendency of its side chain to participate in hydrophobic interactions (see isoleucine ). The amino acid was isolated from casein (milk protein) in 1901, and its structure was established in 1907.
Thom ate so much turkey on thanksgiving he couldnt move for hours. that Bastard had OD'ed on Tryptophan
by State November 25, 2004
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Turkey does have the makings of a natural sedative in it, an amino acid called tryptophan. Tryptophan is an essential amino acid, meaning that the body cannot manufacture it. The body has to get tryptophan and other essential amino acids from food. Tryptophan helps the body produce the B-vitamin niacin, which, in turn, helps the body produce serotonin, a remarkable chemical that acts as a calming agent in the brain and plays a role in sleep. So you might think that if you eat a lot of turkey, your body would produce more serotonin and you would feel calm and want a nap.

That was the conclusion that led many people to begin taking a dietary supplement of tryptophan in the 1980s as a way to treat insomnia, but the U.S. Food and Drug Administration banned tryptophan supplements in 1990 because of an outbreak of eosinophilia-myalgia, a syndrome that causes muscle pain and even death. The FDA said contaminated tryptophan supplements caused the outbreak.

But nutritionists and other experts say that the tryptophan in turkey probably won't trigger the body to produce more serotonin because tryptophan works best on an empty stomach. The tryptophan in a Thanksgiving turkey has to vie with all the other amino acids that the body is trying to use. So only part of the tryptophan makes it to the brain to help produce serotonin.

It is the whole traditional Thanksgiving meal that can produce that after-dinner lethargy. The meal is quite often heavy and high in carbohydrates -- from mashed potatoes, bread, stuffing and pie -- and your body is working hard to digest that food. Also, if you drink alcohol with your dinner, you will likely feel its sedative effect, too.

There is a way to take advantage of the tryptophan in turkey. If you have trouble getting to sleep one night while there is still leftover turkey in the refrigerator, you could have a late snack of turkey and that, nutritionists say, might be the right amount of tryptophan on an empty stomach to help produce some serotonin.
Eat too much turkey, and you'll be asleep by 7 o'clock! That damn tryptophan!
by Sir_Bryce November 24, 2005
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"It's the tryptophan!" is a phrase that is said by someone who has taken Modafinil and Red Bull during Thanksgiving when everyone is eating Turkey that contains Tryptophan and are also eating rice and corn and salad and pie and flan and lasagna and soda. Then during a superhero movie or a movie about aliens or maybe a cartoon, your family starts sleeping and then you say "It's the Tryptophan!" since Tryptophan makes you sleepy.
Mom: Cooks turkey.

Dad: sets the table and gets the soda.

Brothers: sits down.

You: *has a Redbull and a Modafinil.
Everyone: Eats Thanksgiving meal.

Everyone: *watches movie and starts falling asleep.

You: It's the Tryptophan!
by HawaiianPunch1 January 14, 2023
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The state of consciousness one enters after eating a load of turkey on Thankgiving. Also occurs after eating leftovers.
After chowing down their Thanksgiving dinner, nobody seemed to notice Walker Texas Ranger was on the TV due to their tryptophanic comas.

Beware of those driving around the weekend after Thanksgiving. Most are tryptophanic.
by J.Edward December 4, 2008
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An overload of tryptophan in the body causing the body to feel very tired which causes the mouth to curse excessively. Almost the same affect as drunkenness.
Tiffany: Randy had a really bad case of tryptophanity today.
Me: yeah, he had way too much turkey. He was cursing like a sailor.
by webbster158 November 30, 2011
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The drowsy feeling that you get from eating too much turkey and the related amino acid Tryptophan.
After Thanksgiving dinner, I started watching the football game and the next thing I knew I was out cold. I got tryptophaned.
by mikelj November 26, 2009
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The feeling of absolute fullness and slight drunkenness after eating large amounts of turkey.

wow grandma, that meal was fuckin' tryptophan-tastic
by Taco_Exchange November 27, 2007
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