Provided is a composition for promoting hair growth comprising platelet-derived growth factor-D (PDGF-D)-treated adipose-derived stem cells (ASCs) as an active ingredient, and more particularly, a therapeutic agent for hair loss comprising ASCs with increased proliferation and migration by PDGF-D and increased expression and secretion of a growth factor as an active ingredient. PDGF-D-treated ASCs have improved hair regenerative potential through the increases in proliferation, migration and growth factor secretion and thus are useful for a therapeutic agent for hair loss or a cosmetic for preventing hair loss.
