Researchers and advocates have been trying for some years to launch the TAME trial to assess the effects of metformin on aging in humans. This is not with the hope of producing meaningful effects on the progression of aging. Metformin has a small effect size, being one of the less effective interventions that upregulates cellular stress responses, a strategy that in and of itself is weak in long-lived species such as our own. The goal is to push the FDA into accepting clinical trials that target mechanisms of aging rather than a specific named age-related condition. Metformin was chosen because its safety profile, widespread use, and length of time as an approved drug make it hard for the FDA to object on technical grounds.
I view this whole exercise as an example of the harmful distorting effect of regulation on progress in medicine: years of effort and tens of millions of dollars will be wasted on an exercise that everyone involved knows will produce only tiny gains in health and longevity at the end of the day. In a sane world, those resources could