Protocol for systematic review and meta-analysis on the effect of natural products use on blood pressure in Iran

Background: Today, hypertension is a significant public health problem globally, widely recognized as a major risk factor for death. Blood pressure-lowering herbal medicines and natural products have been used for centuries. The protocol aims to determine the effect of natural product use on blood pressure in Iran using data from previously published randomized controlled trials. The current protocol for a systematic review and meta-analysis is designed to determine the effect of natural product use on blood pressure in Iran. Methods: The protocol is developed using PICO (participants, interventions, comparisons, and outcomes) items to assess the effect of natural products on blood pressure reduction in randomized clinical trials (RCTs) in Iran. Specific MESH terms will be used to search Google Scholar, PubMed, and the Cochrane Central Register for randomized controlled clinical trials, as well as national databases such as Barekat Gostar, SID, Magiran, and IranDoc. The I2 index and the Q-test will be used to examine heterogeneity in the effect sizes of individual studies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) of RCTs will be reported per Cochrane guidelines, and all forms will be based on validated Cochrane templates. Discussion: This protocol will detail the effects of natural products (interventions) in comparison to a placebo or other control group (comparators). Registration: The current protocol was also registered on PROSPERO (ID: CRD42021231837, https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=231837, Date: February 18, 2021).