Hi. I know someone with peripheral neuropathy who is on prednisone and finds it super helpful in pain. RSD is different but I do feel what works for one may not for another. I am think prednisone helps with inflammation though I am not sure and often is given for auto immune. I think the concern is getting off it but again I may not be correct. What dose of Cymbalta are you on as now I am on 120mg but before I was on too low of a dose so I did not see benefits. I think it takes time. Is the amino acid a supplement? There is a section for that and you may want to do a search cause I am not familiar. Many thoughts and better wishes