Hi . How wonderful that Metformin has been effective for you for so long! Most people who have issues with Metformin experience negative side effects in the first few weeks of use. It certainly is not for everyone, but it seems to be well-tolerated for those who make it through the early doses. The biggest concerns with long-term use are vitamin B deficiency, which your doctor can monitor you for, and lactic acidosis, which is rare. Here is an article about Metformin that might interest you: https://type2diabetes.com/living/metformin-pharmacist. I hope you get lots of input from others in the community, especially those who have taken it for a long time, like you. Best wishes. - Lori (Team Member)