SLEEP INDUCED BY L-TRYPTOPHAN - EFFECT OF DOSAGES WITHIN THE NORMAL DIETARY-INTAKE

Previous results have demonstrated sleep-inducing effects of L-tryptophan in doses of 1 to 15 g at bedtime. The present laboratory study extends the dose-response curve downward, comparing doses of Vi g, 'A g, and 1 g of L-tryptophan with placebo, in 15 mild insomniacs (subjects who reported sleep latencies of over 30 minutes). One gram of L-tryptophan significantly reduced sleep latency: The lower doses produced a trend in the same direction. Stage IV sleep was significantly increased by V g of L-tryptophan. These results at low doses have interesting implications since the normal dietary intake of L-tryptophan is V2 g to 2 g per day. © 1979 by The Williams & Wilkins Co.