The big key to arthritis is magnesium. See the magnesium page.
Apart from checking for allergies etc., an overlooked therapy is pregnenolone, it was used before NSAIDS but as it can’t be patented etc... but I’ve seen it make significant improvements for RA quickly time and time again.
Msm sulphur and boron can also be important
Also we can recommend thymus supplements, since the Germans have clinical studies on that.