Thymosin β₄increases hair growth by activation of hair follicle stem cells

The study from December 4, 2003, found that Thymosin β4, a polypeptide, significantly promotes hair growth by activating hair follicle stem cells. It was observed that Thymosin β4 increases the migration and differentiation of hair follicular keratinocytes from the hair follicle bulge region, which is a stem cell niche. The presence of Thymosin β4 led to increased migration and differentiation of clonogenic keratinocytes and elevated expression and secretion of matrix metalloproteinase-2, an enzyme important for extracellular matrix remodeling. These results suggest that Thymosin β4 plays a crucial role in hair growth by enhancing stem cell migration, protease production, and differentiation, which are key processes in the hair follicle cycle. However, the number of subjects in the study was not provided, making it difficult to assess the study's strength.