I only have known Metformin to be used for diabetes, but you should look it up and see if it ever even hints at being used for that. I never saw it myself and I'm a nurse who had a liver transplant. As far as your liver being destroyed by the time you are 25, I don't know how old you are, but that is highly unlikely. Never ever heard of someone having their liver destroyed by a fatty liver at 25. It has to go through a very long slow process of progressing to being cirrhoisis of the liver before it would ever destroy it. A lot of people have a fatty liver and don't even know it and nothing more comes of it. It just stays fatty and that is it. In some people though, it can progress to a condition known as NASH and then onto being cirrhosis. This can take many many years, even over a decade to occur if it's going to happen at all.
I certainly don't want you to ignore the problem because it can be a very big problem if it progresses over time, but you need not think you are dying. I would ask the doctor and look at the test results as to how much fat is in your liver to kind of pinpoint how bad of a problem it is. If it's 5-10%, that's actually normal and nothing to worry about. There is really no way that Metformin would ever prevent cirrhosis from happening in a fatty liver if it is destined to progress to NASH and then cirrhosis (this is the correct spelling for it if you want to look it up). I really don't understand what this doctor is doing myself and would really question it myself. If you don't have diabetes, then I would question whether or not metformin would be good to take since it can lower your glucose level. I don't believe it will do anything for a fatty liver.
nurse and liver transplant recipient