Vaping (the use of an e-cigarette) is a common practice among teenagers; 26.7% of high school students report vaping in the last 30 days (Johnston, Miech, O'Malley, Bachman, Schulenberg, and Patrick 2019), making this issue highly relevant. In order to make an informed decision about the use of e-cigarettes, students need to understand the impacts of vaping on their body, which makes the science content engaging and meaningful. Socio-scientific issues (SSI) are real-world issues with clear ties to science ideas and societal concerns, such climate change, resource management, and antibiotic resistance (Sadler, 2004). Using an SSI approach to teaching science can result in increased student learning in science content, nature of science ideas, and understanding of science practices (Eastwood, Sadler, Zeidler, Lewis, and Applebaum, 2012; Klosterman and Sadler, 2010; Zangori, Peel, Kinslow, Friedrichsen, and Sadler, 2017). This article describes a high school biology unit which uses the issue of e-cigarette regulation to teach homeostasis, feedback loops, body system hierarchy, and macromolecules. In order to make an informed decision about the use of e-cigarettes, students need to understand the impacts of vaping on their body, which makes the science content engaging and meaningful.