I have been just diagnosed with MG and my main symptom was a droopy eyelid. I haven't been back to the Dr. since being confirmed by blood tests but the Dr. has put me on 60 MG twice daily of Mestinon (Generic). Since I don't see the Dr for a little more than a week still I haven't got any answers as to how long it takes for the drug to kick in. I have seen a slight improvement and have had side effects include muscle twitching in my sleep which led to soreness throughout the body and also one bout of uncontrollable bowel movement. I would like to know about how long your experiences were to noticeable improvement. Since driving is a big part of my job, I have concerns that I can keep on doing it.