Most of us assume that the effects of a pill like metformin would take years to produce any appreciable effect on aging, but maybe not. An admittedly small study of healthy volunteers claimed that the DNA methylation age of blood cells is reversed within a week and, astoundingly, only ten hours after taking a single 850 mg pill of metformin.26 But clearly more work is needed with greater numbers of subjects to know for sure if metformin can delay the aging clock over the long run.
