Tryptophol is an aromatic alcohol found as a secondary product of alcoholic fermentation that induces sleep in humans. Typically synthesized in yeasts it is also produced by the trypanosomal parasite Trypanosoma brucei resulting in sleeping sickness. Tryptophol is a possible functional analog of serotonin or melatonin and shows genotoxicity in vitro. Saccharomyces cerevisiae uses it as a quorum sensing molecule.

Tryptophol is used as a precursor to the synthesis of tryptamines like DMT and the drug indoramin along with TNF-alpha modulators. When administered to rodents it resulted in significantly depressed antibody production.