Female reproductive aging precedes physical aging and is closely associated with the development of many aging-related diseases. With the delay in the human reproductive age, delaying reproductive aging and improving fertility have become important challenges for biomedical research. Arachidonic acid (AA) was found to significantly prolong the reproductive lifespan and enhance the quality of senescent oocytes in a cryptic nematode model. In a mouse model of senescence, AA supplementation improved the ovarian reserve, increased the oocyte number and quality, and restored fertility. Further analysis showed that AA delayed ovarian senescence by restoring lysosomal activity in the germ lines of senescent nematodes and mice and enhancing lysosomal functions in oocytes and ovarian granulosa cells. This study provides preliminary evidence that AA could serve as a potential intervention strategy for reproductive senescence and offers new ideas for improving reproductive health in older women.