anyone changed insulin before?.

When I was first diagnosed, I was taking Humalog. A couple months later, I changed to Novolog due to a change in insurance (or something like that, I'm not exactly sure what happened), but right before Thanksgiving, I was switched back to Humalog, which is what I am currently on. Both insulins work for me, so I just have to make sure that I take it.

I've moved around the world quite a bit. I first used Lantus from Singapore, then Humalog in Toronto & Myanmar, now Insuget 70/30 in Manila. The latter change due to the availability of low cost insulin on Phillipine Government program. No problems.

yeah I change because insulin looses its effectiveness in me. You might need to change doses because no two insulins act in the same way, I would recommend reducing your dose initially and monitoring closely.