A growth factor is a chemical compound, most often of a polypeptide orsteroid, capable of inducing cell growth, proliferation, regeneration, or celldifferentiation phenomena.

Growth factors often act as intracellular signaling molecules, examplesbeing cytokines and hormones, which bind to specific receptors on thesurface of target cells. They induce differentiation and cell maturation, butthe process depends on each factor. For example, epidermal growthfactor (EGF) induces osteogenic differentiation, while fibroblast andvascular endothelial growth factors induce angiogenesis.

Active Regeneration is the clinical application of regenerative proceduresusing healthy hair cells from the same patient to improve affected areas.Active Regeneration relies exclusively on its ability to produce healthy hairfollicles by "triggering" areas of poor hair growth on the patient's scalp.