I know it isn't suppose to work as well as methadone. It has for me since the beginning of my spinal trouble. I took it for 6 years before my surgery, and again had good pain contol. Take it now in low dose and it does get rid of the NP. I read about the receptors too. My pain specialist was willing to put me on methadone too, but he said if the bridge isn't broken don't fix it. I know one other person who is taking morphine and it works for her too. Don't know why I am lucky in this regard. Most people need more than what I am taking, or a combination of meds. I will count my blessings. Maybe it works better because I know he is willing to adjust my meds if I ever need it. I have no anxiousnes or worry about the pain, no stress. That helps too. thanks for all your posts too. Have a peaceful holidays and take care of yourself. ginnie