Shark cartilage is extracted from the heads and fins of sharks. Cancerous tumors require a network of blood vessels to survive and grow. In theory, taking cartilage may prevent blood vessels from forming, thus starving the cancerous tumor and causing it to shrink or perhaps even disappear. At this time, however, it is not known which proteins are responsible for this effect. Don't Get Cancer in which cartilage was promoted as a cancer cure.
Shark cartilage is available as a food supplement in capsule and powder form.
These products do not have any effect on cancer because the protein molecules in these products are too large to be absorbed by the human gut. At this time, scientific studies have produced no evidence that shark cartilage can prevent or cure cancer in humans. Some researchers are trying to purify anti-angiogenic substances from cartilage. If this effort is successful, the clinical usefulness of such substances could then be studied. For the present time, the most promising anti-angiogenic compounds are those that have been purified from sources other than cartilage or have been synthesized in the laboratory.