Mine hurt for several months no matter what I tried-rest, stretching, exercises. Sharp pain any time lifting or moving straight out. Hard time even putting on a jacket or shirt. Didn't want to pay hundreds to have it looked at, but finally bothered me enough that I thought I would try it and if it didn't work, I just get the refund and see a doctor. Took about 5-6 weeks, but the pain was completely gone. Saw noticeable difference just a week or 2 into it.