The influence of altered tryptophan availability on ethanol intoxication in normal men.

Because of evidence that altered 5-hydroxytryptamine function may modulate ethanol intoxication, we investigated this in normal social drinkers. Using amino acid mixtures, 5-hydroxytryptamine was influenced by altering levels of its precursor tryptophan. Neither raising nor lowering tryptophan affected alcohol intoxication as measured by a self-report scale and memory and motor tasks. Our data do not support the idea that 5-hydroxytryptamine can modulate alcohol-induced intoxication.