I had done some yard work aboput a week age and my lower back was a little sore but getting better. I used one of the pills Saturday night and noticed my back pain was more intense and constant beginning Sunday late morning. Still uncomfortable this morning (Monday). Could this be aggrivation of original soreness or is it Staxyn related. Didn't notice back pain the first time I used Staxyn. This is the second time using it. Other than back pain, both wife and I are very pleased with the results.