Osteoarthritis (OA) is the most common form of joint disease. Although OA was previously thought to be a progressive, degenerative disorder, it is now known that spontaneous arrest or reversal of the disease can occur. Conventional medications are often effective for symptom relief, but they can also cause significant side effects and do not slow the progression of the disease. Several natural substances have been shown to be at least as effective as nonsteroidal anti-inflammatory drugs at relieving the symptoms of OA, and preliminary evidence suggests some of these compounds may exert a favorable influence on the course of the disease.