Biggest supporter of metformin:

https://www.lifeextension.com/Magazine/2017/4/Metformin-Slashes-Cancer-Risks

Written April 2017, with 57 citations

Most promising data

dom-12354-fig-0002-c

15% higher survival rate using metformin over control over 5  years.

Can people with type 2 diabetes live longer than those without? A comparison of mortality in people initiated with metformin or sulphonylurea monotherapy and matched, non‐diabetic controls, 2014

 

However, Some disagree because it lacks good RCTs for HEALTHY NON-DIABETIC individuals. It also lacks clinical evidence for boosting of human longevity- Especially maximal lifespan.

At 14.12s, shows a 2012 meta of RCTS, showing poor Relative Risks(RR)

What is the mismatch?

Future studies:
1. Targeting Aging with Metformin (TAME),