Dr. SPIESEL: Well, that supplement is a mixture of two things, one is called glucosamine, one is called chondroitin sulphate.

NPR: Slate's Medical Examiner: Doubts on Supplements

And I should say that one of my wife's doctors has a cat and she says that this cat cannot get up in the morning without a little dose of glucosamine and chondroitin sulphate.

NPR: Slate's Medical Examiner: Doubts on Supplements