BPC-157 is a 15-amino-acid sequence isolated from a partial fragment of a protein found in human gastric juice. In academic literature it is referred to as Body Protection Compound 157. Most cited research originates from the Sikiric group at the University of Zagreb. Documented preclinical investigation spans soft-tissue signaling, gastric mucosal integrity, vascular pathways, and the nitric oxide system.

TB-500 is a synthetic peptide based on the active region of thymosin β4 (Tβ4), a naturally occurring 43-amino-acid protein first isolated from the thymus gland. Tβ4 is one of the most-studied actin-sequestering proteins in the human body. Documented preclinical investigation spans tissue regeneration, cardiac repair models, ocular surface healing, and inflammatory regulation.

Both compounds are most-cited alongside investigations of angiogenesis, actin cytoskeletal remodeling, and tissue regeneration pathways in animal models. Neither has been approved by the FDA for any therapeutic indication. Both remain classified as research compounds.