Yes, I was off Gemfibrozil in three weeks and got my legs back about a month later. Trust me, I was counting the days.
When I googled those side effects I got the impression that the injurious effects could be permanent under certain circumstances. Maybe your friend should quit.
My friend won’t quit. I have told him it can be permenant but he seems to think losing his legs is a good price to pay for living longer. I told him he was full of it because there was really no proof he was going to live longer, but he won’t listen to me. That is what fear of dying does to people. As far as I am concern I will die with my legs working rather than voluntarily stopping their function.