A Fishy Therapy

A thriving but controversial dietary supplement

Shark cartilage is for sale all over the Web. Powders of it, packaged in jars and capsules, are among the products offered at sites specializing in herbal remedies, vitamins, health wares, and bodybuilding aids. These Internet sites claim that the cartilage skeletons of sharks and their close relatives—skates and rays—offer various health benefits.