Dr. David Sinclair's lab has published and repeated that treating old female mice (16 months, equivalent to 65-70 human years) with a chemical rejuvenates their eggs, potentially producing new ones.

“Research co-authored by David Sinclair and published in the journal Cell Reports in February 2020 supports this claim. The study showed that treating aged female mice with the chemical NMN (nicotinamide mononucleotide), a precursor to NAD+, restored the quality of their oocytes (eggs) and increased live birth rates. News reports and Sinclair himself have described this as reversing the reproductive clock in mice. While the primary finding was about rejuvenating existing eggs, not creating new ones, the Sinclair Lab's website does state a goal of reactivating ovarian stem cells. Context: ⚠️ Actual number differs by >10%. The study primarily focused on restoring the quality of existing eggs in aged mice, which had declined due to lower levels of the molecule NAD+. The chemical NMN was administered in the mice's drinking water for four weeks.”