The short answer
Shark cartilage has been sold for decades as a cancer remedy. The FDA has not approved cartilage to treat cancer. In the largest trial, adding a shark cartilage product to standard treatment for advanced lung cancer did not help people live longer. Talk with your care team before taking any supplement.
The FDA has not approved cartilage from sharks or cows as a treatment for cancer.
In a large trial of 379 people with advanced lung cancer, adding a shark cartilage product to standard treatment did not help them live longer.
A smaller trial in advanced breast and colon cancer found no difference in survival or quality of life.
Cartilage products sold as supplements are not drugs and are not meant to treat, prevent, or cure disease.
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The simple version
This page is for anyone who has seen shark cartilage pills or powders sold as a cancer treatment. The short answer: when shark cartilage was tested in people with cancer, it did not help them live longer. The FDA has not approved cartilage as a treatment for cancer.
Shark cartilage has been tested, and it did not work in people.
Where the idea came from
For years, people said that sharks do not get cancer. NCI notes that cancers have in fact been found in sharks. Some researchers also wondered whether cartilage could stop tumors from growing new blood vessels. Tumors need blood vessels to grow. These ideas were worth testing, and they were tested.
What happened in studies of people
NCI describes what researchers found:
- Lung cancer. A large trial included 379 people with advanced non-small cell lung cancer. Everyone got chemotherapy and radiation. Some also got a shark cartilage product, and some got a placebo. NCI reports there was no difference in how long people in the two groups lived.
- Breast and colon cancer. A trial of 83 people with advanced breast or colon cancer found no difference in quality of life or survival between the shark cartilage group and the placebo group.
A lab idea can look promising and still not help people. That is why trials in people matter.
What is sold in stores
NCI says a number of cartilage products are sold in the United States as dietary supplements. These are not drugs, and they are not meant to treat, prevent, or cure diseases.
NCI lists nausea, vomiting, stomach cramps, bloating, and constipation as common side effects of shark cartilage.
Red flags to watch for
The FDA warns that fake cancer products often use phrases like "treats all forms of cancer," "selectively kills cancer cells," or "more effective than chemotherapy." It also warns that these products may cause harm by delaying or interfering with proven treatments.
Talk with your care team
If you are taking shark cartilage or thinking about it, tell your care team. Bring the bottle or a photo of the label. They can check whether it could affect your treatment. If you want to try something new, ask whether a clinical trial could fit you.
Sources
- NCI, Cartilage (Bovine and Shark) (PDQ), Patient Version: https://www.cancer.gov/about-cancer/treatment/cam/patient/cartilage-pdq
- FDA, Products Claiming to "Cure" Cancer Are a Cruel Deception: https://www.fda.gov/consumers/consumer-updates/products-claiming-cure-cancer-are-cruel-deception
Common questions
Is shark cartilage approved to treat cancer?
No. NCI says the FDA has not approved cartilage as a treatment for cancer.
Was shark cartilage ever tested in people?
Yes. NCI describes a large trial in 379 people with advanced non-small cell lung cancer. People who got a shark cartilage product with chemotherapy and radiation did not live longer than people who got a placebo with the same treatment.
Why do people think it works?
An old belief held that sharks do not get cancer (cancers have since been found in sharks), and that cartilage might stop tumors from growing new blood vessels. That idea led to studies. When products were tested in people with cancer, they did not show a benefit.
Does it have side effects?
NCI says shark cartilage commonly causes nausea, vomiting, stomach cramps, or bloating.
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Your next step
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Plain-language explanation of the published sources cited on this page. AI-assisted, source-checked, not clinician-reviewed.
Sources last checked: 2026-09-27 what this meansLast updated: 2026-09-27Next planned review: 2027-03-27
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
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How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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