The effect of lavender on stress in individuals: A systematic review and meta-analysis

Lavender is considered as one of the medicinal plants to manage stress. Although many preliminary studies evaluated the effect of lavender on individuals’ stress level, to the best of our knowledge, we did not find a study that summarizes the results. Therefore, the present study aimed to estimate the Pooled effect of lavender on the stress level of individuals using systematic review and meta-analysis. A systematic literature review based on PRISMA 2020 was performed on the SID, MagIran, Embase, PubMed, Scopus, Web of Science (WoS) databases, and Google Scholar motor engine using related MeSH/Emtree and ‎Free Text words,‎ including “Lavender*”, “Lavandula*”, “Stress*”, “Stress Disorders, Traumatic”, and “Stress, Psychological” with no time limitation until August 2021: We also searched two Iranain free local resourses including MagIran https://www.magiran.com and Scientific Information Database (SID) https://www.sid.ir. The quality assessment of studies was performed using JBI checklist. Heterogeneity among studies was quantified using I2 index and Random Effects model was used to combine the data and perform the meta-analysis. In the initial search, 1520 articles were found. After excluding the irrelevant studies, finally, 21 articles with a sample size of 791 in the intervention group and 804 in the control group were included in the meta-analysis. As a result of combining the studies, stress score after using lavender in the intervention group showed a significant decrease of 0.63 ± 0.13 (95% CI) more than that in the control group (P