Here is a good study showing how Metformin, a very inexpensive drug used to treat Type 2 diabetes, slowing brain and organ aging in male monkeys.

Many functional medicine clinicians take metformin themselves based on prior research and anecdotal evidence suggesting that metformin has some degree of anti-aging component. These previous studies involved giving rodents, flies, and worms metformin found hints of rejuvenation.

Monkeys, biologically, are much closer to humans than flies (obviously).

It is unclear whether its potential anti-ageing effects are achieved by lowering blood sugar or through a separate mechanism.

https://medicalxpress.com/news/2024-09-metformin-aging-male-monkeys.html