U.S. consumers spent $753 million in 2012 on supplements of glucosamine and chondroitin in an attempt to relieve pain and stiffness from arthritis, according to the Nutrition Business Journal.

While chondroitin sulfate and glucosamine sulfate both have well-documented, beneficial effects in patients with osteoarthritis, the exact molecular actions of these drugs are also unknown.

Glucosamine and chondroitin sulfate aid in joint health ... 4health pet foods feature the finest proteins and supplemental nutrition for the optimal health of dogs and cats.

Each 8-ounce serving has 1,500 milligrams of glucosamine hydrochloride and 200 milligrams of chondroitin sulfate, along with green-tea extract and vitamins C and D. Orthopedic surgeon Kevin Stone ...