The cell that builds and maintains connective tissue—it produces collagen, the structural protein in skin, tendons, and organs.Fibroblasts are the primary cell type of connective tissue, responsible for synthesizing extracellular matrix components including collagen, elastin, fibronectin, and glycosaminoglycans. They play central roles in wound healing (migration, contraction, matrix remodeling) and fibrosis (excessive matrix deposition). Several peptides on Peptidings interact with fibroblast biology: GHK-Cu stimulates fibroblast collagen synthesis, BPC-157 promotes fibroblast migration to injury sites, and antimicrobial peptides modulate fibroblast inflammatory responses.