The U.S. Food and Drug Administration (FDA) does not approve exosome therapy for hair loss as of yet, since it is still under study to see if there are any long-term risks associated with this therapy. While exosomes have shown promise in early research and some clinical trials, their use in hair restoration is still considered experimental. The FDA has stringent regulations and guidelines to ensure the safety and efficacy of new treatments, and exosome therapy still needs to meet these requirements for approval in the context of hair loss.