L-tryptophan

noun

L-tryp·​to·​phan ˈel-ˈtrip-tə-ˌfan 

: the levorotatory form of tryptophan that is a precursor of serotonin and was used formerly as a dietary supplement especially to promote sleep and relieve depression

Examples of L-tryptophan in a Sentence

Recent Examples on the Web

Not just another gourmet candy bar, the dark chocolate with lavender and blueberry flavors is infused with the hormone melatonin, the amino acid L-tryptophan, a blend of soothing botanicals and something called PharmaGABA, an artificial version of a neurotransmitter that calms the brain. —Karen Kaplan, Los Angeles Times, 4 Dec. 2024

This could be due to ingredients like ginger or L-tryptophan, which can irritate sensitive stomachs. —Amber Smith, Discover Magazine, 5 Aug. 2023

With a unique blend of hemp seed oil, Thiamine, and L-tryptophan, these chews effectively reduce stress and tension in dogs, promoting a sense of calm. —Amber Smith, Discover Magazine, 4 July 2023

Word History

First Known Use

1949, in the meaning defined above

Medical Definition

L-tryptophan

noun

L-tryp·​to·​phan ˈel-ˈtrip-tə-ˌfan 

: the levorotatory form of tryptophan that is a precursor of serotonin and was formerly used in some health food preparations in the belief that it promoted sleep and relieved depression see eosinophilia-myalgia syndrome