My spinal surgeon recommended I try this (for my back and knee pain): P.E.A. (Palmitoylethanolamide). It is a naturally occurring fatty acid which works as a pain killer and anti-inflammatory. The daily dose she recommended was 1200 milligrams, easing to 600 after it had taken effect (a couple of weeks). You can view some case studies here.
WARNING: Do not confuse this supplement with Phenethylamine which is a quite different thing altogether. Your search engine might confuse the two.
I expected it would take approx three weeks to get any relief but I had very significant relief after a bit over a a week. The only other effect I had was a slightly dry mouth which has eased now that I have dropped back to 600. My knee pain (bone on bone arthritis) which had been very painful all the time has eased to no pain at all most of the time. Usually I can walk for five km now with no pain at all – this is after only two weeks! I have just been able to complete a two day canoe trip I was prevented from doing up till now.
I bought it from these people (100 x 300 mg caps for A$60 delivered – two days). If you have some chronic persistent pain (and hate opiates as much as I do – they also do me little good) you might give some a try! The above compounding pharmacists are very helpful. They will ring you to discuss the product. really!
PS: Should you suffer from symptoms of dry mouth (for any reason – it is not even a listed side effect of P.E.A; just unlucky I guess) you should try Biotene which will relieve it for up to four hours: Biotene – available from any chemist