332f662d_Supplements_for_Pain__effectiveness
[supplement & summary] Chondroitin sulfate. Known as being “good for cartilage” because it is major component of cartilage, and it has much in common with glucosamine (they are often sold together). Chondroitin sulfate is chemically complex, and it’s almost impossible to know what you’re really getting. [safety] “well tolerated for up to three years,” but many known rare and minor side effects [more information] Wikipedia [effectiveness] 
heavily studied, but no clear good news,8 and a huge slam from the NEJM in 20069
Supplements for Pain
effectiveness