Society of Diabetic Nephropathy Prevention Journal of Nephropathology 2251-8363 11 4 2022 09 06 Protocol for systematic review and meta-analysis on the effect of natural products use on blood pressure in Iran e17290 e17290 10.34172/jnp.2022.17290 EN Mohammad Azadbakht https://orcid.org/0000-0002-6298-8718 Alireza Fatahian https://orcid.org/0000-0001-6398-3831 Seyde Sedighe Yousefi https://orcid.org/0000-0002-0204-0837 Mahmood Moosazadeh https://orcid.org/0000-0002-5452-514X Moloud Fakhri https://orcid.org/0000-0001-6995-9779 Journal Article 10.34172/jnp.2022.17290 2021 09 23 2022 05 25 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).