ICMR-National Institute of Nutrition

Tryptophan (Trp; W) is an essential amino acid and a natural precursor for important metabolites such as serotonin and nicotinamide, in the latter case giving it vitamin-like properties through its ability to replace dietary niacin. The mood-lifting effects of L-tryptophan are particularly worth noting due its conversion to the neurotransmitter serotonin. Tryptophan decreases appetite and reduces anxiety.

Nutrition atlas