I am on met-no adverse reactions . I am a type 2 diabetic and have taken it for ten years. You might be interested in the recent story on met . They believe it may prolong life spans by as much as 50 percent because it oxygenates your cells , I don't know if I believe all that , its just nice to know they don't think it shortens it . I take 4 ea 500mg er a day . I have lost weight but because I was on a strict diet . It is very old stable drug and if you take it with food and not have a adverse reaction its a good one . It is generic and fairly cheap . If anything it tends to constipate me . We are all different .