It works after 2.5 weeks.
I had a very bad nerve pain on my neck which started 8 weeks ago. The first month the pain was very bad, and it moved from left to the right side. I couldn't sit for 30 minutes, and working at the computer bought so much pain it was hard for me to focus. Even though I was consciously taking hourly breaks throughout the day and doing mild stretches, I could barely manage my daily activity, but the pain did not reduce too much. I ordered this product from Amazon marketplace, and started using it 2.5 weeks ago. I followed the instructions religiously, which was 15 minutes everyday, it could be any time of the day. These couple of days the pain reduced to a manageable level, and I could actually move my head from side to side without much problem. Even my friends could tell the difference. I understand neck pain has different causes and intensity, it also depends on how you take care of yourself, what kind of bed/pillow you use, etc. This product may not be for everyone, but it helps me and I'd like to share my experience here for everyone's reference.
Rating: 4 stars