It's not always easy to decide when a patient does or doesn't respond to treatment.

And in an illness like MG, where you don't have very good parameters to follow and it can fluctuate so much any how, it is even harder.

My personal rule of thumb is that true improvement means that it lasts for more than 6 months. ( I have had so many short term improvements and worsening that I realized by now that it is just the "crazy" course of this illness).

The same applies for true worsening.
I nearly stopped taking mytelase, because I had a severe exacerbation (following a viral infection) that lasted for more than 2 months, which made me feel it wasn't really working that well any more. Fortunately, my neurologist insisted that I keep on taking it, as I didn't have any significant side effects and just felt it was useless, and I gradually went back to the improvement I had with it before that exacerbation.

As I said, it is not easy to know with this illness, and that is why it is good to have someone you can trust to help you with that.