Definition
Research conducted before human trials, including in vitro studies and animal models.
Preclinical research covers all work done before a compound is tested in humans: in vitro assays, cell culture, and in vivo animal studies examining pharmacology, mechanism and toxicology. A compound with only preclinical data has not been evaluated for safety or efficacy in people. Clinical development then proceeds through phase 1 (safety and pharmacokinetics in small groups), phase 2 (preliminary efficacy) and phase 3 (large confirmatory trials) before regulatory review. Many research peptides, including BPC-157, the TB-500 fragment, MOTS-c and FOXO4-DRI, remain predominantly preclinical. Evidence level should always be read against the stage of research it comes from.