Hello all. I am new to the site. My question is does it take a few days for Xanax XR to build up in your system before you get the full effects. I am a disabled veteran and have been on Xanax for about 8 years now, but only the IR Xanax. I battled the addiction to it for years before I was able to control myself. Because of that my tolerance is really high. I got sick of the IR because it would A) wear off to fast and B) it takes me a lot of mgs to get relief. I've tried the other benzos, like Klonopin and Ativan. My doctor gave me a weeks worth of XR 3mg and I am on my third day now and I do not really notice a difference. My doctor and I were hoping that this would work and if it did I would be on XR 3MG twice a day and one 2mg IR for breakthrough panic attacks. So can someone please help me and let me know does it take a few days before it really starts to work good or should I just go to four 2mg IR. I am actually pretty educated on these types of meds, but I have never been on Xanax XR so I never researched it before. Please help me and thank you guys. I am also on Cymbalta which has helped me tremendously.