Tryptophan is most often used for Sleep.

Tryptophan

Written by:

•Last Updated: August 28, 2025

Tryptophan is an amino acid that is needed in the body to build proteins and neurotransmitters. It is an essential amino acid, meaning that it cannot be synthesized by the body and therefore must be obtained from dietary sources.

Last Updated:August 28, 2025

Research FeedRead all studies

No effect of whey protein, tryptophan, and theanine-containing supplements on sleep

In this randomized crossover trial in 17 physically active men (average age of 25), multicomponent supplements that contained whey protein, tryptophan, and theanine did not improve sleep quality.

Coenzyme Q10, magnesium, and tryptophan supplement shows mixed results for fibromyalgia

Does skim milk enriched with ashwagandha improve sleep quality?

L-tryptophan supplementation for constipation in older adults

No effect of tryptophan supplementation on attention or impulsivity in adults