Preclinical trials refer to the stage of drug or medical product development that takes place before human clinical trials. To describe this stage of research, there are several synonyms that can be used. They include animal studies, preclinical research, preclinical testing, nonclinical trials, and preclinical development. All of these phrases are effective in conveying the meaning of the preclinical trial stage. They are essential in ensuring that any potential side effects or safety issues are discovered before a product moves on to human testing. The preclinical stage is necessary to ensure that products are as safe and effective as possible before being tested on human subjects.