C-based nanocomposites have emerged as promising candidates for reducing pharmaceutical contaminants in water sources. Pharmaceutical contaminants (such as antibiotics, painkillers, and hormones) pose environmental and health risks. Hence, there is a requirement of advanced treatment methods. This chapter explores the advancements and applications of C-based hybrid nanocomposites in drug degradation processes. C-based nanocomposites have unique structural, chemical, and electronic properties. The chapter begins with an overview of the various types of pharmaceutical contaminations, their environmental impact, and their geo-prospective occurrence in water resources. C-based nanomaterials, such as graphene oxide (GO) reduced graphene oxide (rGO), carbon nanotubes (CNTs), carbon dots, activated carbon (AC), and fullerene (C60) have some limitations. Hence, their collaboration with nanoscale metals and metal oxides enhances their performance effectively in catalytic degradation processes. This chapter highlights the synthesis methods and functionalization techniques. It focuses on the mechanisms (adsorption capabilities, photocatalytic activities, and redox reactions) by which these nanocomposites facilitate drug degradation. Different case studies of specific drug degradation such as antibiotics, anti-inflammatory, and other persistent pharmaceutical compounds are examined. They illustrate the practical lab or industry-based applications. Furthermore, the chapter addresses the environmental and health safety of C-based nanocomposites considering their potential toxicity and the challenges associated with their use in real-world applications. It also discusses the current limitations, such as scalability and economic feasibility and the ongoing research aimed at overcoming these barriers. Additionally, C-based nanocomposites represent a significant advancement in the field of drug degradation, offering efficient, versatile, and sustainable solutions. Continued research and development are crucial to fully exploit their potential and to implement these technologies on a larger scale to mitigate pharmaceutical pollution in the environment.