Metformin

Preliminary studies suggest that metformin may actually slow aging and increase life expectancy, possibly by improving the body's responsiveness to insulin, antioxidant effects, and improving blood vessel health.

Because the vast majority of research regarding metformin included only people with diabetes or prediabetes, it's unclear whether these potential benefits are limited to people with those conditions, or whether people without diabetes may derive benefit as well.

https://www.health.harvard.edu