https://www.selleckchem.com/products/pfk158.html Excessive Internet use can negatively affect academic performance, family relationships and emotional development among the youth. Such issues have been identified as Internet addiction (IA). We aimed to determine the prevalence of IA among Portuguese adolescents and assess how parental control can relate to IA. An observational cross-sectional study was performed at public schools within a Portuguese region, using Young's Internet Addiction Test survey. General sociodemographic and emotional well-being data were obtained. A descriptive and bivariate analysis was done among Internet-addicted and average users, followed by a logistic regression analysis. Adjusted odds ratios (aORs) were computed with two-sided values<.05 for statistical significance. A total of 1916 eligible responses were obtained. Mean age was 15±1.8 years, with a slight predominance of female (53.3%) participants. In our sample, 16.5% were deemed Internet addicted and less likely to have any parental control over Internet use (aOR 0.74, <.05). Moreover, 28% of the Internet-addicted users were less likely to have control over time spent online (aOR 0.72, <.05), and close to half were unlikely to have online content restrictions (aOR 0.56, <.01). Our findings reported a significant rate of Internet-addicted youth. IA was negatively related to parental control. Whenever any kind of parental control over Internet use was reported, IA was less likely to occur. Healthcare professionals should be aware of the risks of IA in adolescents to improve its prevention and intervention. Our findings reported a significant rate of Internet-addicted youth. IA was negatively related to parental control. Whenever any kind of parental control over Internet use was reported, IA was less likely to occur. Healthcare professionals should be aware of the risks of IA in adolescents to improve its prevention and intervention. To assess the usefulness of serum ferritin and sol