Preclinical
Research conducted in cell cultures or animal models before a compound advances to human clinical trials, used to assess basic safety, efficacy, and mechanism of action.
Preclinical research includes in vitro (cell-based) and in vivo (animal) studies and is required by regulatory agencies before any compound can be tested in humans. The majority of research peptides — including BPC-157, TB-500, and Epithalon — have extensive preclinical data but have not been evaluated in formal human clinical trials.
Preclinical results are an essential first step but do not guarantee the same outcomes in humans. Biological differences between rodents and humans, dosing differences, and the complexity of human disease mean that many compounds with strong preclinical profiles fail in clinical trials. When reviewing peptide research literature, noting whether data comes from preclinical or clinical studies is critical for accurate interpretation.