Designer drugs, which are psychoactive substances with ever-changing compositions, pose a significant challenge in terms of detection and treatment within the community. Given that medical students will play a crucial role as future doctors, there is a greater need for them to acquire knowledge about these substances. A total of 614 medical students participated in the study survey. In terms of knowledge level, 76.3% of students were familiar with synthetic marijuana, 70% with strox, and 53.3% with crystal myth. Social media platforms served as the primary source of knowledge for 70% of students, followed by friends (54%) and TV (49%). Regarding student perceptions, the majority (90%) believed that taking designer drugs is prohibited by religion, social norms, and the law. Additionally, 90% of students agreed that social media platforms are effective in increasing awareness about the risks of designer drugs, although more than 37% acknowledged that social media reports could potentially increase curiosity to try these substances. While only 20.4% had encountered patients using designer drugs, approximately 92% expressed a desire for more information on these substances to better fulfill their duty of raising awareness in society (87%). Findings of this study bring attention to the knowledge, attitudes, and perceptions of medical students at Cairo University regarding the issue of designer drugs. While their knowledge level is generally acceptable, participants expressed a need for more information, highlighting the importance of incorporating additional education on designer drugs into the medical curriculum.