Are the adverse effects of metformin working through creating high insulin levels it produces, and as dangerous as this source says?

This is a key insight that is important in speaking to why this pharmacological approach is faulty in its conception, because it is creating one problem to solve another, and that is often the case when medication is employed. The part that is understood and logical to the biochemist is often only part of the story in what is needed, and the remedy may be similarly only partly understood, and then you have a prescription for long-term problems because, in effect, you are fighting fire with fire; it might put one fire out but substitute another that will take a toll over time, and that is the problem with metformin.