For millions of women, diminished ovarian reserve represents a quiet closing of doors — a biological countdown that current medicine can slow but not reverse. Researchers at Peking University People's Hospital have now demonstrated, in animal models, that stem cells harvested from fat tissue may do what no existing therapy has managed: coax damaged ovaries back toward function. The findings, rooted in the cellular mechanics of oxidative stress and a form of cell death called ferroptosis, open a corridor toward human trials and, perhaps, a new chapter in reproductive medicine.