Introduction Alopecia is a common disorder that severely affects the mental well-being and quality of life of those affected, yet available treatment options remain limited. Emerging evidence suggests that exosomes from diverse cellular sources possess therapeutic potential for alopecia. However, research on the application of platelet-rich plasma-derived exosomes (PRP-exos) in promoting hair growth is still relatively sparse. This study aims to elucidate the effects of PRP-exos on hair growth and to investigate the associated molecular mechanisms. Methods We employed conventional molecular biology techniques to evaluate the impacts of PRP-exos on hair follicle stem cells (HFSCs) in terms of proliferation, apoptosis, and migration, as well as their protective effects against oxidative stress. A murine model of alopecia was utilized, and the effectiveness of subcutaneously administered PRP-exos on hair growth was assessed through histological analysis. Additionally, RNA sequencing (RNA-seq) was conducted to explore the potential pathways mediating the effects of PRP-exos on hair growth. Results Our results demonstrate that PRP-exos significantly enhance both the proliferation and migration of HFSCs while concurrently inhibiting apoptosis and mitigating oxidative stress-induced damage. The subcutaneous injection of PRP-exos fostered hair regeneration in mice, marked by an increase in hair follicle counts of the anagen phase and dermal thickening. Importantly, we found that treatment with PRP-exos upregulated the expression of SIRT1, leading to the deacetylation of FoxO3a and a subsequent reduction in oxidative stress effects. Conclusions Ultimately, our findings suggest that PRP-exos facilitate hair regeneration by modulating the SIRT1/FoxO3a pathway, providing more evidence for their clinical application in alopecia management.