Test Your Knowledge

There are several types of glucosamine and chondroitin that may be used to make supplements. Both substances can be combined with different salts, sulfates or minerals (potassium or iodine). Both can also come in oral (pill, powder, liquid), injectable (intravenous, intramuscular or subcutaneous) or topical form (creams and eye drops).  Types include:

• Glucosamine sulfate (also known as chitosamine). An artificial salt of glucosamine and important for repair and maintenance of cartilage. It is the most commonly used form of glucosamine in supplements. Studies show the substance may inhibit enzymes that act to break down cartilage and may prevent cartilage loss in those who already have osteoarthritis. According to the Natural Standard Research Collaboration (NSRC) (an international group that reviews research on complementary and alternative therapies), this form appears to be the most effective against osteoarthritis.
  
  
• Glucosamine hydrochloride (HCL). Also commonly sold in supplements, this form provides more glucosamine than glucosamine sulfate.
  
  
• N-acetyl glucosamine. A key component of bandages and patches used to control hemorrhaging (bleeding) in minor injuries or during interventional cardiology radiology procedures (such as cardiac catheterization). This form is also sold in supplements.
  
  
• N-acetyl D-glucosamine. A form of glucosamine often used by researchers when conducting clinical trials but also sold in supplements.
  
  
• Chondroitin sulfate (also known as chonsurid or chondroitin sulfuric acid). The most widely used form of chondroitin in supplements, it is composed of galactosamine sulfate and glucuronic acid (the moisturizing component of collagen). The substance was first extracted and purified in the 1960s. There are several forms (such as C, A and A sodium).
  
  
• Chondroitin sulfate-sodium hyaluronate. A form of chondroitin used as a tissue lubricant during eye surgery and as part of a prescription eye solution to treat keratoconjunctivitis (inflammation of the conjunctiva and cornea).