Chondroitin, glucosamine and methylsulfonylmethane, or MSM, are commonly found, either separately or together as a complex, in supplements marketed for joint health. They are also taken for relieving pain associated osteoarthritis -- a painful degenerative condition that results in stiff, achy joints. These substances may offer anti-inflammatory and pain-relieving benefits, taken alone or in combination. However, results have been mixed. Talk to your doctor before taking supplements of any kind, especially if you have an existing condition.

Chondroitin Cushions Joints

Chondroitin is a major constituent of the connective tissue in your body known as cartilage, which helps cushion your joints and prevent your bones from rubbing against each other. Chondroitin absorbs water and other fluids, which helps keep your cartilage hydrated and healthy. It's taken as a supplement to treat osteoarthritis, a form of arthritis that results from the breakdown of cartilage. Clinical data has yielded mixed results, with some research finding a benefit, and other data showing no benefit, according to the University of Maryland Medical Center.

Glucosamine and Joint Health

Like chondroitin, glucosamine is produced naturally in your body and plays a role in joint health. It helps build and repair cartilage that connects the joints. It's common to take glucosamine alone or with chondroitin for osteoarthritis. Glucosamine possesses anti-inflammatory properties, and data suggests it may help relieve osteoarthritis pain, according to the American Academy of Orthopaedic Surgeons. While data to support pain relief is promising, research showing that supplementation helps repair or restore cartilage is lacking, according to the academy.

Methylsulfonylmethane and Osteoarthritis

MSM is a sulfur-containing compound that helps support tendons and muscles. Because of MSM's pain-relieving and anti-inflammatory properties, researchers examined whether it had benefits alone or in combination with glucosamine for knee osteoarthritis. In the study, 118 adults with mild-to-moderate knee osteoarthritis took MSM and glucosamine alone or in combination for 12 weeks. Researchers found MSM and glucosamine effectively relieves knee osteoarthritis pain and that the combination of the two produces even better results.

Taking the Complex

The combination of chondroitin, glucosamine and MSM is used to support healthy joints and taken to reduce pain in those with osteoarthritis and other inflammatory joint problems. If you choose to take the chondroitin, glucosamine and MSM complex, take it as directed by your doctor. The complex may cause nausea, upset stomach, heartburn or diarrhea. These side effects are typically mild, according to Drugs.com. This supplement may interact with certain medications, such as blood thinners and insulin. Talk to your health care provider if you're currently taking prescribed medication.