Charles River is a non-clinical contract research organization (CRO) providing essential products and services to help pharmaceutical and biotechnology companies, government agencies, and academic institutions with their research and drug development efforts. The company has three reportable segments – Research Models and Services (RMS), Discovery and Safety Assessment (DSA), and Manufacturing Solutions. Through the RMS segment, the company supplies research models to the drug development industry and related services that are designed to support clients in the use of research models in drug discovery and development. The DSA business segment provides services that enable customers to outsource innovative drug discovery research, related drug development activities, and regulatory-required safety testing of potential new drugs, vaccines, industrial and agricultural chemicals, consumer products, veterinary medicines, and medical devices. The Manufacturing Solutions segment comprises three businesses – microbial solutions, biologics solutions, and avian vaccine services. Microbial solutions products and services businesses provide in vitro methods for conventional and rapid quality control testing of sterile and non-sterile pharmaceuticals and consumer products. Biologics testing solutions offer the testing of biologics frequently outsourced by pharmaceutical and biotechnology companies. The avian vaccine services business provides specific-pathogen-free (SPF) fertile chicken eggs, SPF chicken, and diagnostic products used to manufacture vaccines, primarily veterinary vaccines.

The company is involved in the discovery of clinical candidates and the design, execution and reporting of safety assessment studies for various types of compounds, including small and large molecule pharmaceuticals, industrial and agricultural chemicals, vaccines, consumer products, veterinary medicines, cell and gene therapies, biocides and medical devices.