The Facts

• These two compounds have been the subject of a number of studies to assess their impact on osteoarthritis. Unlike glucosamine sulfate, chondroitin shows indications that it may also provide nutritive support for atherosclerosis, high cholesterol and kidney stones. Glucosamine is more narrowly applied to osteoarthritis. It appears to be most effective on the knees. Chondroitin is effective for all joints. The human body manufactures both compounds and both are sold as dietary supplements. Chondroitin supplements are composed of animal cartilage or synthesized materials. Glucosamine sulfate is commonly derived from chitin, a compound often harvested from the exoskeltons of arthropods.
  
  

Function

• Functionally the two substances have very different roles. Chondroitin acts as a flexible connector in cartilage. Glucosamine is a building block used to manufacture cartilage, ligaments and tendons. Chondroitin plays a crucial role in the joints, particularly where it helps to retain nutrients and water. That is essential because of the lack of blood flow to cartilage. To help make the distinction it could be said that glucosamine helps provide the building blocks for skeletal materials while chondroitin helps to reduce degradation of existing materials.
  
  

Features

• The absorption rate is a critical factor when comparing the two compounds. Glucosamine has an absorption rate of more than 90 percent. Chondroitin's rate is about 12 percent. The absorption rate of chondroitin is negatively influenced by the large size of the molecule. With these figures, a consumer might see glucosamine as a clear choice given the fact that at least 85 percent of the chondroitin ingested with be excreted. However chondroitin's broad effect may offset these concerns.
  
  

Considerations

• Consumers should be skeptical of all studies. A meta-analysis conducted by TE Towheed and colleagues was published by The Cochrane Collaboration. The study purported to examine glucosamine as a treatment for osteoarthritis but treated glucosamine HCl and glucosamine sulfate as interchangeable when they are demonstrably different. The published work gave no credit to glucosamine as an aid for arthritis. Other factors that influence the efficacy of glucosamine include duration and severity of a patient's osteoarthritis. Patients who are overweight and suffer from severe symptoms of osteoarthritis are less likely to obtain relief.
  
  

Warning

• A number of standard warnings are associated with any dietary supplement. Although these products are natural they may have an adverse effect on a developing fetus, so women that are pregnant or may become pregnant should avoid these products. Other concerns are drug-related interactions. Consumers are urged to speak to a pharmacist to determine the safety of these materials. In addition, glucosamine sulfate is often derived from shellfish so anyone with a shellfish allergy should avoid these products. The key point for all of these warnings is to speak to a a qualified practitioner before beginning a dietary supplement regimen.