Has anyone been having problems with aching joints with the recent batch of mercury pharma levoxathyrine? My lower back and thighs are so painful that I am having difficulty walking any distance. I noticed the symptoms after about a week of taking my latest prescription and asked my pharmacist if it was a different make. He said it was my usual brand, however he has kindly said he will get me another brand for my next prescription. I read on the forum that there were problems a few years ago.