Balneotherapy -- Well-designed studies, primarily conducted in Israel, suggest that balneotherapy (including sulfur baths with or without mud packs or soaks in the Dead Sea) can help treat several different kinds of arthritis, including osteoarthritis (OA), rheumatoid arthritis (RA), and psoriatic arthritis. People who took sulfur baths and other spa therapies improved strength, decreased morning stiffness, had better walking ability, and decreased inflammation, swelling, and pain in joints, particularly in the neck and back. Mud packs and Dead Sea salts dissolved in a regular bath tub also improved symptoms of arthritis, but not as effectively as the Dead Sea itself.
MSM -- MSM is a popular supplement for treating the pain of arthritis, including both OA and RA, despite a lack of scientific evidence. One preliminary study suggested that 6,000 mg of MSM did improve pain and function without side effects in people with OA of the knee. Some preparations of MSM combine the mineral with glucosamine to treat OA. One study suggests that approach might be effective, but more research is needed.
DMSO -- Several studies have also suggested that DMSO, applied in creams, may reduce pain and swelling in people with RA and OA, but not all studies agree. More research is needed.