I’ve taken it for over two and a half years and suffer no side defects now. I had a few gastric effects in the first two weeks only. As for anti ageing I’ve heard some say that about it. However at the same time as starting Metformin I started a low carb diet and lost a shed load of weight, so I have to say I think my face has aged as I no longer have fat filling up the wrinkles!
I don't buy into it any more than I buy into statins or any other drug that we apparently need in order to fix everything that nature has been doing wrong for the past 2.5 million years
For what it matters, I used Metformin for over a year and I don't have any issue with it. I do, however, have an issue with popping pills 'just in case'. Humans don't have a Metformin deficiency. When it comes to pharmaceuticals, and everything they allegedly do and don't do, I trust nothing and no one.
I think you would be better off looking at Carnosine in this respect.
Reputedly Carnosine can increase the Hayflick limit in human fibroblasts, as well as appearing to reduce the telomere shortening rate. It is also considered as a geroprotector.
It is believed Carnosine acts as an antiglycating agent, reducing the rate of formation of advanced glycation end-products (substances that can be a factor in the development or worsening of many degenerative diseases, such as diabetes, atherosclerosis, chronic kidney failure, and Alzheimer's disease), and ultimately reducing development of atherosclerotic plaque build-up. Chronic glycolysis is speculated to accelerate aging, making carnosine a candidate for therapeutic potential.