Key factors implicated in aging include reactive oxygen species, inflammatory processes, insulin resistance, and mitochondrial dysfunction. All are exaggerated in transgenic growth hormone mice (TGM), which display a syndrome resembling accelerated aging. We formulated a complex dietary supplement containing 31 ingredients known to ameliorate all of the above features. We previously showed that this supplement completely abolished the severe age-related cognitive decline expressed by untreated TGM. Here we report that longevity of both TGM and normal mice is extended by this supplement. Treated TGM showed a 28% increase (p < .00008) in mean longevity. An 11% increase in mean longevity was also significant (p < .002093) for treated normal mice, compared to untreated normal mice. These data support the hypothesis that TGM are a model of accelerated aging, and demonstrate that complex dietary supplements may be effective in ameliorating aging or age-related pathologies where simpler formulations have generally failed.