I have chronic back pain...not really SI-related, though. I have spondylolisthesis (slipped vertebra) at my L5/S1. I wake up every morning with back pain. For the most part, stretching and using my inversion table first thing out of bed, gets me to the point where I can at least stand up straight and be mobile. Then by the time I get to the gym, my back has loosened up enough where I'm good to go...until I sit down again for a long period of time (like at my desk at work). I have found OTC NSAIDS to not be very helpful for my particular situation...and Lord knows, I've tried 'em all at some point. I will occasionally pop an Aleve or Advil after a particularly long and grueling ride, but I have to be honest and say that I don't notice much (if any) pain relief from it. What did work for me, was taking Celebrex (which is a prescription NSAID marketed for arthritis). It was prescribed to me by my foot doctor last year when she thought I might have arthritis in my some of my toes. She wrote the script for a 1-month suppy and told me to give it a try and see if my toe pain improved. I took 1 Celebrex pill per day...it didn't do much for my toe pain, but my lower back felt wonderful...so that was an unexpected bonus. Of course, since I was only taking it on a "trial" basis, she didn't specify refills, so once I finished the bottle....no more Celebrex. I suppose I could always ask my primary doc to write me a script for it, but I manage okay without it...for now.