How to Take 5-HTP With or Without Food. Part of the series: LS ֠Your Health Questions Answered. 5-Hydroxytryptophan is an amino acid that serves as the precursor to serotonin and melatonin by tryptophan. Take 5-HTP with or without food with help from an expert in nutrition and health in this free video clip. Read more:http://www.livestrong.com/video/1010672-5htp-food/