Abstract
OBJECTIVE: This study aimed to perform a systematic review and meta-analysis of stretched, erect, and flaccid penis length as well as circumference according to geographic WHO regions. METHODS: PubMed, Embase, Scopus, and Cochrane Library were searched for articles published until February 2024. Studies in which a healthcare professional evaluated the penis size were considered eligible. After assessing the risk of bias, a systematic review and meta-analyses were performed according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement, and the outcomes were grouped based on the WHO regions. RESULTS: A total of 33 studies comprising 36 883 patients were included. The risk of bias in the included studies was moderate/low. A comprehensive systematic review was done and meta-analyses performed for flaccid length [n = 28 201, mean (SE) 9.22 (0.24) cm], stretched length [n = 20 814, mean (SE) 12.84 (0.32) cm], erect length [n = 5669, mean (SE) 13.84 (0.94) cm], flaccid circumference [n = 30 117, mean (SE) 9.10 (0.12) cm], and erect circumference [n = 5168, mean (SE) 11.91 (0.18) cm]. The mean length of the stretched penis was largest in Americans [14.47 (0.90) cm]. The mean length of the flaccid penis was the largest in the Americas [10.98 (0.064) cm]. The mean flaccid penile circumference was largest in Americans [n = 29 714, mean (SE) 10.00 (0.04) cm]. CONCLUSIONS: Penis sizes vary across WHO regions, suggesting the need to adjust standards according to geography to better understand councilmen and their partners. These data provide a framework for discussing body image expectations and therapeutic strategies in this sensitive and emotional subject matter.