The aim of the present study was to investigate the efficacy of Passiflora incarnata herbal tea on human sleep, as measured using sleep diaries validated by polysomnography (PSG). Forty-one participants (18–35 years) were exposed to each treatment for a week, whereby they consumed a cup of the tea and filled out a sleep diary for 7 days, and completed Spielberger's state-trait anxiety inventory on the seventh morning. If you're hoping passionflower tea will help you sleep, the evidence for the brewed tea is one small 2011 trial that found a modest gain in self-rated sleep quality after a week. The aim of the present study was to investigate the efficacy of Passiflora incarnata herbal tea on human sleep, as measured using sleep diaries validated by polysomnography (PSG). PubMed® comprises more than 40 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full text content from PubMed Central and publisher web sites. pubmed.ncbi.nlm.nih.gov In one double-blind, placebo-controlled study, 41 participants (18–35 years) drank a cup of tea made with Passiflora incarnata L. and wrote in a sleep diary for seven days and 10 of these participant underwent overnight polysomnography on the last night.