The National Academies of Sciences, Engineering, and Medicine (NASEM) released a comprehensive report in January 2018, titled *Public Health Consequences of E-cigarettes*, reviewing the health effects of electronic cigarettes (e-cigarettes). The report, authored by Gideon St. Helen and David L. Eaton, among others, addresses the diverse set of battery-powered devices that deliver nicotine-containing aerosols. Key findings include: 1. **Toxicity and Nicotine Intake**: Conclusive evidence shows that e-cigarettes contain and emit potentially toxic substances, but exposure levels are generally lower than with combustible cigarettes. Nicotine intake from e-cigarettes is highly variable and can be comparable to that from combustible cigarettes among experienced adult users. 2. **Long-term Health Effects**: No evidence was found to link e-cigarette use to long-term health effects due to the relatively short history of e-cigarettes. However, evidence suggests biological effects, such as increased heart rate and respiratory symptoms in adolescents. 3. **Smoking Cessation**: Limited evidence supports the effectiveness of e-cigarettes as smoking cessation aids, particularly those with nicotine. More frequent use is more effective. There is insufficient evidence to compare e-cigarettes to FDA-approved treatments. 4. **Harm Reduction**: Complete substitution of combustible cigarettes with e-cigarettes reduces exposure to toxicants and carcinogens, potentially leading to reduced adverse health outcomes. A population dynamic model suggests a net public health benefit over the next 30 years. 5. **Research Needs**: The report identifies gaps in knowledge and recommends improved research methods, including cohort studies and randomized controlled trials. 6. **Policy Implications**: Physicians should integrate questions about nicotine and tobacco use in pediatric care and consider biomarker screening for active youth users. They should encourage FDA-approved medications for smoking cessation and provide behavioral support for those using e-cigarettes. The report concludes that while e-cigarettes pose less risk than combustible cigarettes, more research is needed to address long-term effects and improve research methods.The National Academies of Sciences, Engineering, and Medicine (NASEM) released a comprehensive report in January 2018, titled *Public Health Consequences of E-cigarettes*, reviewing the health effects of electronic cigarettes (e-cigarettes). The report, authored by Gideon St. Helen and David L. Eaton, among others, addresses the diverse set of battery-powered devices that deliver nicotine-containing aerosols. Key findings include: 1. **Toxicity and Nicotine Intake**: Conclusive evidence shows that e-cigarettes contain and emit potentially toxic substances, but exposure levels are generally lower than with combustible cigarettes. Nicotine intake from e-cigarettes is highly variable and can be comparable to that from combustible cigarettes among experienced adult users. 2. **Long-term Health Effects**: No evidence was found to link e-cigarette use to long-term health effects due to the relatively short history of e-cigarettes. However, evidence suggests biological effects, such as increased heart rate and respiratory symptoms in adolescents. 3. **Smoking Cessation**: Limited evidence supports the effectiveness of e-cigarettes as smoking cessation aids, particularly those with nicotine. More frequent use is more effective. There is insufficient evidence to compare e-cigarettes to FDA-approved treatments. 4. **Harm Reduction**: Complete substitution of combustible cigarettes with e-cigarettes reduces exposure to toxicants and carcinogens, potentially leading to reduced adverse health outcomes. A population dynamic model suggests a net public health benefit over the next 30 years. 5. **Research Needs**: The report identifies gaps in knowledge and recommends improved research methods, including cohort studies and randomized controlled trials. 6. **Policy Implications**: Physicians should integrate questions about nicotine and tobacco use in pediatric care and consider biomarker screening for active youth users. They should encourage FDA-approved medications for smoking cessation and provide behavioral support for those using e-cigarettes. The report concludes that while e-cigarettes pose less risk than combustible cigarettes, more research is needed to address long-term effects and improve research methods.