There are no miracle drugs or therapies for anti-aging, except for life style changes, such as low caloric, low refine sugar and intermittent fasting, that have shown evidence of effectiveness. You may then opt for plant based diets to insure less inflammatory reactions in body and organs that will age the organism. Metformin is a dangerous drug with multiple side effects and the worst is kidney damage. Read here https://www.rxlist.com/consumer_metformin/drugs-condition.htm#what_are_side_effects_of_metformin