Adipose-derived stem cells (ASCs) have been used in tissue repair and regeneration. Recently, it was reported that ASC transplantation promotes hair growth in animal experiments, and a conditioned medium of ASCs (ASC-CM) induced the proliferation of hair-compositing cells in vitro. However, ASCs and their conditioned medium have shown limited effectiveness in clinical settings. ASC preconditioning is one strategy that can be used to enhance the efficacy of ASCs and ASC-CM. Therefore, we highlighted the functional role of ASCs in hair cycle progression and also the advantages and disadvantages of their application in hair regeneration. In addition, we introduced novel ASC preconditioning methods to enhance hair regeneration using ASC stimulators, such as vitamin C, platelet-derived growth factor, hypoxia, and ultraviolet B.