Important subject, metformin is good stuff for diabetics, possibly very good for the rest of us, more studies needed. I'm 66 and though I have BMI of 27, blood glucose around 100, I talked my doctor into letting me take 500 mg Metformin/day. Apparently, it is an effective mTOR inhibitor for those not willing to take Rapamycin (and risk low levels of immunity). I also take 500 mg Ashwagandha & glucosamine (together, said to mimic Metformin), plus 1000 mg Red Rice Yeast, and occasional Turmeric teas and sildenafil, all of which are mTOR suppressors, good for endothelial health. That, along w about 7 hrs of exercise a week and <1800 cal/day and I feel great! Granted I was pretty healthy to begin with, but I almost feel better than ever. I live in a retirement community and note that most don't really work out, at a time when they should. My blood work, liver and kidney markers are good, crp low. Exercise particularly helps...you can feel it working. It really helps you sleep better at night. No drastic weight loss on Metformin for me, still working on getting BMI to about 25-26 (the final frontier). Many say ideal BMI is 26 for those working out, also that crp is more important marker than cholesterol for heart health.