BRIEF COMMUNICATION: Sleep Induced by L-Tryptophan

Abstract

Sleep-inducing effects of L-tryptophan in doses of 1-15 g at bedtime were shown. The dose-response curve was extended downward, comparing doses of 1/4, 1/2 and 1 g of L-tryptophan with placebo, in 15 mild insomniacs (subjects who reported sleep latencies of over 30 min). L-Tryptophan at 1 g significantly reduced sleep latency, the lower doses produced a trend in the same direction. Stage IV sleep was significantly increased by 1/4 g of L-tryptophan. The results at low doses have interesting implications since the normal dietary intake of L-tryptophan is 1/2-2 g/day.