Aging clocks—DNA methylation-based prediction models—promise to measure biological age and pace of aging, but recent clinical trials reveal significant limitations in translating clock scores into meaningful health outcomes, raising questions about their clinical utility as consumer tools. Epigenetic aging clocks use DNA methylation patterns at hundreds of thousands of CpG sites to predict biological age or mortality risk, yet different clocks often yield discordant results measuring different aspects of biology. The DO-HEALTH trial found omega-3 supplementation moved three of four aging clocks by approximately three months of aging over three years, but effect sizes were small and it's unclear whether these molecular shifts translate to meaningful health benefits.