I've been taking metformin off-label for weight loss, and it's been working well. I'm a little annoyed that I have to resort to off label stuff because I too have Cigna and I have not been successful at getting them to cover it.

I think it's more my employer's fault than anything else; fortunately metformin actually seems to be doing the job. They won't cover that either but even without insurance it's so cheap that it's not worth complaining about.