Human sleep and 5-HTP. Effects of repeated high doses and of association with benserazide (RO.04.4602).

On account of the conflicting data concerning the action of 5-HTP on human sleep, repeated high doses were administered to three healthy subjects. The paradoxical sleep time and percentage tend to show a decrease during the 2nd week of treatment, followed by a rebound effect after the end of the treatment. In two subjects who initially had a small amount of slow wave sleep (SWS), the treatment induced an increase in SWS that persisted after the end of the treatment. Similar results were obtained after administration of 5-HTP together with RO.04.4602.