Neutering older mice extends their lives by a third

Castration extends life span in mice

A preprint from James Nelson's lab at UT Health San Antonio found that castrating male mice in adulthood—around the human equivalent of 30—stretched their lifespan by about 33%, more than neutering before or shortly after puberty. The mice stayed just as frail as controls, so the longevity gain isn't simply better health. The result upends the assumption that the testes must be removed early to affect aging, and hints at future "castration mimetics."