→ Start healthfully with our BMI Weight Loss Calculator

Natural Sources of L-Tryptophan

By Jae Allen

L-tryptophan is an essential amino acid necessary for the production of serotonin. Some people find that boosting their L-tryptophan levels helps alleviate the symptoms of depression or insomnia. However, specific L-tryptophan dietary supplements were banned by the U.S. Food and Drug Administration in 1990 after an outbreak of eosinophilic-myalgia syndrome among users of the supplement. The EMS outbreak was traced to a contaminated batch of supplement; L-tryptophan occurs naturally in food and there is no danger of EMS from eating foods which contain tryptophan.

Pumpkin Seeds

Pumpkin seeds are a natural source of L-tryptophan, with a tryptophan content of 0.576 grams per 100 grams of dried pumpkin seeds. Roasted pumpkin seeds, with or without added salt, have a slightly lower tryptophan content.

Milk and Dairy

Milk naturally contains a small amount of L-tryptophan. In her 2010 book, "Weight Control and Slimming Ingredients in Food Technology," Susan Cho states that L-tryptophan in milk played a part in increasing the sense of satiation or fullness when dietary protein was also consumed. It is believed that this phenomenon relates to the increased production of serotonin when L-tryptophan levels are raised. Therefore, Cho recommends the consumption of milk and dietary protein together as a way to aid weight loss. Other dairy products also contain L-tryptophan; eggs, for example, have 0.167 grams of tryptophan in every 100 grams uncooked. The L-tryptophan content of an egg remains almost the same, 0.166 grams, when cooked.


Turkey is notoriously known for its tryptophan content, although in fact it contains no more L-tryptophan per 100 grams than any other meat. All meats are sources of L-tryptophan, although the effects of such levels of L-tryptophan on the brain are negligible unless you eat the meat on an empty stomach with no other protein present. The popular belief that turkey at Thanksgiving causes sleepiness is a myth; sleepiness after a turkey feast is more likely due to general overeating and alcohol consumption.

Video of the Day

Brought to you by LIVESTRONG
Brought to you by LIVESTRONG

More Related Articles

Related Articles