Bisphenol A (BPA) is a widely produced chemical found in many consumer products, including plastics, food containers, and metal can linings. Biomonitoring studies show that BPA is present in the urine, blood, and tissues of humans worldwide, indicating widespread exposure. However, some toxicokinetic studies suggest that humans are not internally exposed to BPA, which contradicts the findings of biomonitoring studies. The authors of this review examined over 80 biomonitoring studies and two toxicokinetic studies to understand why these results differ. They found that BPA is commonly detected in blood and urine, with unconjugated BPA present in blood and conjugated BPA in urine. These findings suggest that humans are exposed to BPA and are at risk from internal exposure to unconjugated BPA. The two toxicokinetic studies that suggested human BPA exposure is negligible have significant deficiencies and are not reliable for risk assessment purposes. The review also discusses the methods used in biomonitoring studies, including the use of ELISA and other analytical techniques, and the importance of proper sample collection and storage to ensure accurate results. The review highlights the importance of biomonitoring studies in assessing human exposure to BPA and the need for further research to understand the health effects of BPA exposure.Bisphenol A (BPA) is a widely produced chemical found in many consumer products, including plastics, food containers, and metal can linings. Biomonitoring studies show that BPA is present in the urine, blood, and tissues of humans worldwide, indicating widespread exposure. However, some toxicokinetic studies suggest that humans are not internally exposed to BPA, which contradicts the findings of biomonitoring studies. The authors of this review examined over 80 biomonitoring studies and two toxicokinetic studies to understand why these results differ. They found that BPA is commonly detected in blood and urine, with unconjugated BPA present in blood and conjugated BPA in urine. These findings suggest that humans are exposed to BPA and are at risk from internal exposure to unconjugated BPA. The two toxicokinetic studies that suggested human BPA exposure is negligible have significant deficiencies and are not reliable for risk assessment purposes. The review also discusses the methods used in biomonitoring studies, including the use of ELISA and other analytical techniques, and the importance of proper sample collection and storage to ensure accurate results. The review highlights the importance of biomonitoring studies in assessing human exposure to BPA and the need for further research to understand the health effects of BPA exposure.