I read in one of the clinical trials discussing NAC that they believed it could still have some benefits for those with longer standing (COLD) RSD.
I suffer terribly from cold so I decided to give it a trial and I took it for 3 months. It helped to improve my tolerance for cold quite a bit.
My only problem now is that I've been hit with major waves of hot flashes so I thought it best to go off it until I get my hormones back in balance. I'm afraid I'm quit a fright to look at with heat packs wrapped around my leg while I sticking my head in the freezer