Bovine and marine cartilage

What it is

These are dried, powdered animal cartilage preparations. Shark cartilage is taken from the endoskeleton of sharks and contains proteins, proteoglycans, glycosaminoglycans, minerals, carbohydrate and lipid; bovine cartilage is usually taken from cattle trachea. Because of how it is harvested, shark cartilage can be contaminated with other shark tissue, heavy metals and microbial material. It is the raw material from which chondroitin and glucosamine are extracted.

What the research says

The cancer claim has been tested and failed. Two double-blind placebo-controlled randomised trials, one in 379 patients with stage III lung cancer and one in 83 patients with advanced breast or colorectal cancer, found no survival benefit. Laboratory work does show anti-angiogenic activity, but that has not translated into human results, and there are no published studies showing anti-angiogenic activity in whole animals by mouth. The joint-health rationale rests on chondroitin, a cartilage extract that does beat placebo for osteoarthritis pain in pooled trials, rather than on whole cartilage powder. Shark cartilage products have also been found to contain the neurotoxin BMAA and mercury.

Evidence grade: Not supported by the research.

What goes wrong

Fifteen of sixteen commercial shark cartilage supplements tested contained the cyanobacterial neurotoxin BMAA, and all shark fin products tested contained mercury. (Source 1)

• Lab study in cells, Low certainty.
• Size: 16 commercial shark cartilage supplement products.
• Who: Retail supplement products, not people.
• How long: Single laboratory analysis.
• Result: BMAA detected in 15 of 16 products at 86 to 265 μg/g dry weight; low concentrations of total mercury in all shark fin products.
• Funding: not stated.

We report here that BMAA was detected in fifteen out of sixteen products with concentrations ranging from 86 to 265 μg/g (dry weight).

Shark cartilage is usually mildly tolerated but rare serious adverse events reported to safety databases include hepatitis and neurological effects. (Source 2)

• Expert review, not systematic, Very low certainty.
• Size: Not stated; safety database summary.
• Who: People taking shark cartilage supplements.
• How long: Not stated.
• Result: Common: taste disturbance, nausea, vomiting, dyspepsia, constipation, dizziness, erythema, hypotension. Rare serious: altered consciousness, weakness, hepatitis, hyperglycaemia, hypoglycaemia, peripheral oedema.
• Funding: Not applicable.

Serious adverse events are rare and can include altered consciousness, decreased motor strength, decreased sensation, generalized weakness, hepatitis, hyperglycaemia, hypoglycaemia, and peripheral oedema.

Shark cartilage preparations are frequently contaminated by other shark tissue and possibly heavy metals and microbial material because of how they are harvested and processed. (Source 3)

• Expert review, not systematic, Low certainty.
• Size: Not applicable.
• Who: Commercial shark cartilage preparations.
• How long: Not applicable.
• Result: Contamination with shark liver tissue containing squalamine, possible mercury, and bacterial and viral contaminants.
• Funding: Not applicable.

Because of harvest conditions, preparations are often contaminated by other shark tissues (e.g., shark liver containing squalamine) and possibly by heavy metals (e.g., mercury) and bacterial and viral contaminants acquired during storage and/or processing.

Bovine cartilage products have been associated with altered taste, fatigue, dyspepsia, fever, dizziness and scrotal oedema, and with local inflammation when injected. (Source 4)

• Expert review, not systematic, Very low certainty.
• Size: Not stated.
• Who: People treated with the Catrix bovine cartilage product.
• How long: Not stated.
• Result: Altered taste, fatigue, dyspepsia, fever, dizziness, scrotal oedema; injection site inflammation and redness with parenteral use.
• Funding: Not applicable.

Altered sense of taste, fatigue, dyspepsia, fever, dizziness, and edema of the scrotum following treatment with Catrix® bovine cartilage product

In 2000 the US Federal Trade Commission barred the main promoter of shark cartilage from claiming it prevents, treats or cures cancer without substantial evidence. (Source 2)

• Official position, Certainty not rated.
• Size: Not applicable.
• Who: US consumers.
• How long: Order made in 2000.
• Result: Marketing claims prohibited pending substantiation.
• Funding: Not applicable.

In 2000 Lane was prohibited by the Federal Trade Commission from claiming that

What the evidence supports

A meta-analysis of 26 articles describing 30 randomised trials in knee and hip osteoarthritis found that oral chondroitin, given as a purified symptomatic slow-acting drug at the doses licensed in Europe, relieved pain and improved physical function more than placebo, while glucosamine reached significance only on stiffness. (Source 5)

• Meta-analysis, Low certainty.
• Size: 26 articles describing 30 trials.
• Who: Adults with knee and/or hip osteoarthritis taking isolated glucosamine or chondroitin preparations, not cartilage supplements.
• How long: Varied across the included trials; databases searched from inception to 22 May 2018.
• Result: In the article's Results section the pooled effect for chondroitin versus placebo on pain is given as an effect size of − 0.540 cm [95% CI, − 0.900 to − 0.178 cm], and for function as − 0.462 units (95% CI, − 0.752 to − 0.170 units). The abstract adds that glucosamine reached significance only on stiffness, that combination therapy did not have enough evidence to be superior to placebo, and that there was no significant difference in adverse events or discontinuations versus placebo.
• Funding: not stated on the article page.

Limit of this finding: This evidence is about chondroitin and glucosamine as purified, pharmaceutical preparations. The paper treats them as 'symptomatic slow-acting drugs' and the pooled trials gave about 1500 mg a day of glucosamine and under 800 mg a day of chondroitin, the doses licensed in Europe. Chondroitin sulfate is extracted from animal cartilage, but none of the pooled trials tested a bovine, marine or shark cartilage supplement, which is ground whole cartilage of unstated and variable chondroitin content. So this result says something about a measured dose of isolated chondroitin; it does not show that taking a cartilage supplement relieves osteoarthritis pain, and it should not be read that way.

Given the effectiveness of these symptomatic slow-acting drugs, oral chondroitin is more effective than placebo on relieving pain and improving physical function.

What the evidence does not support

A double-blind placebo-controlled trial of the standardised shark cartilage extract AE-941 in inoperable stage III lung cancer found no survival difference. (Source 6)

• Randomized trial, Moderate certainty.
• Size: 379 patients (188 AE-941, 191 placebo)
• Who: Patients with inoperable stage III non-small cell lung cancer receiving chemotherapy and radiotherapy.
• How long: Median survival followed to 14 to 16 months.
• Result: Median survival 14.4 months (95% CI 12.6 to 17.0) with AE-941 versus 15.6 months (95% CI 13.8 to 18.1) with placebo, P=0.73; no differences in time to progression, progression-free survival or response rates.
• Funding: not stated.

For the primary endpoint overall survival no statistically significant difference was reported between the AE-941 group (n=188; median survival = 14.4 months, 95% CI 12.6 to 17.0) and the placebo group (n=191; median survival = 15.6 months, 95% CI 13.8 to 18.1; P=0.73).

A randomised, placebo-controlled, double-blind North Central Cancer Treatment Group trial of a shark cartilage product in advanced cancer found no survival or quality-of-life benefit. (Source 7)

• Randomized trial, Moderate certainty.
• Size: 83 evaluable patients.
• Who: Patients with incurable breast or colorectal carcinoma with good performance status, receiving standard care.
• How long: Product taken 3 to 4 times each day alongside standard care.
• Result: No difference in overall survival and no suggestion of improvement in quality of life versus placebo.
• Funding: not stated.

There was no difference in overall survival between patients receiving standard care plus a shark cartilage product versus standard care plus placebo.

A monograph review noted that the laboratory anti-angiogenic activity of shark cartilage has never been demonstrated in whole animals given it by mouth. (Source 8)

• Expert review, not systematic, Low certainty.
• Size: Not applicable.
• Who: Preclinical models.
• How long: Not applicable.
• Result: No published whole-animal oral demonstration of anti-angiogenesis at the time of the monograph.
• Funding: Not applicable.

The studies published to date have not been randomized, double-blind, placebo-controlled trials.

Memorial Sloan Kettering states that evidence is lacking for bovine cartilage in cancer or AIDS and that its suggested immune effect has not been shown in humans. (Source 9)

• Official position, Certainty not rated.
• Size: Not applicable.
• Who: General public and patients.
• How long: Page as retrieved in 2026.
• Result: Laboratory results at high doses against cancer cell lines, with little evidence of the same effects in the human body.
• Funding: Not applicable.

It has also been suggested that bovine cartilage may enhance immune response, but this effect has not been shown in humans.

Where the research disagrees

Whether cartilage's anti-angiogenic activity in the laboratory means anything for people

• Promoters of cartilage products, as summarised by Memorial Sloan Kettering, in-vitro: Catrix®, a bovine cartilage product, was used in a lab experiment against isolated samples of several cancer cell lines, with positive results at high doses. (Source 9)
• CAM-Cancer evidence summary, drawing on two randomised controlled trials, rct: Although some uncontrolled studies showed encouraging results, the evidence from two RCTs (n=379, n=83) did not show shark cartilage to prolong survival. (Source 6)

How much

• Reference intake: No reference intake such as an RDA or AI exists for bovine or marine cartilage. It is not a nutrient; it is a processed animal tissue sold as a supplement, and the relevant sources describe it only as a product taken for various conditions. (Source 8)
• Upper limit: No tolerable upper intake level or acceptable daily intake has been set by the bodies we could reach. The nearest official action is the US Federal Trade Commission order of 2000 restricting cancer claims, which is a marketing restriction and not a dose limit. (Source 2)
• Studied: In the North Central Cancer Treatment Group trial the shark cartilage product was given three to four times each day alongside standard care in patients with incurable breast or colorectal carcinoma. (Source 7)
• Studied: The lung cancer trial used the standardised shark cartilage extract AE-941 in 379 patients receiving chemotherapy and radiotherapy for inoperable stage III non-small cell lung cancer. (Source 6)

A common belief, and what the research shows

The belief: Sharks do not get cancer, so shark cartilage must fight cancer.

What the research shows: CAM-Cancer's summary states plainly that its use as an anti-cancer remedy was based on the misconception that sharks cannot get cancer. When the idea was tested properly, a 379-patient lung cancer trial and an 83-patient trial in breast and colorectal cancer both found no survival difference, and the second one was unable to demonstrate any suggestion of efficacy for this shark cartilage product in patients with advanced cancer.

Questions and answers

What is it?

These are powders and extracts made from animal cartilage. Shark cartilage comes from the shark's skeleton; bovine cartilage usually comes from cattle trachea. Chemically they are mostly protein, proteoglycans and glycosaminoglycans with some mineral, carbohydrate and fat. (Source 3)

What does it do in the body?

Swallowed cartilage is digested like any other protein-rich tissue. The reason it was ever taken for cancer is a theory about blood vessel growth rather than an observed effect in people. In osteoarthritis the plausible active fraction is chondroitin, which is extracted from cartilage rather than taken as whole cartilage powder. (Source 9)

Is it good or bad for you?

For cancer, the evidence is negative: two randomised placebo-controlled trials found no survival benefit. For joints, the extracted chondroitin fraction does beat placebo for pain in pooled trials, which is not the same as whole cartilage powder working. Shark cartilage carries a contamination problem that ordinary supplements do not. (Source 6)

How do you get more of it?

Cartilage is sold as dried powders, extracts and capsules, and shark cartilage is also the raw material behind chondroitin and glucosamine products. Nothing in the literature we read supports taking more of it; this is a description of what is sold, not a recommendation. (Source 1)

If it is harmful, what reduces it?

There is nothing stored in the body to remove; the relevant step is simply stopping the supplement. Reported side effects are usually mild and transient, though rare serious events including hepatitis have been recorded in safety databases, and shark products can carry mercury and BMAA. (Source 2)

Why might someone be low in it or missing it?

This does not apply. You cannot be low in dietary cartilage, because it is not a nutrient and the body builds its own cartilage from amino acids and sugars. The only sense in which people are told they are missing it is the marketing idea that swallowed cartilage rebuilds joint cartilage, which has not been demonstrated. (Source 9)

We searched: Searched for cartilage deficiency, dietary cartilage requirement and cartilage status in the NCBI shark cartilage monograph, the CAM-Cancer summary, the Memorial Sloan Kettering monograph and the osteoarthritis meta-analysis; no source describes a deficiency state.

Which whole foods contain it or feed it?

Cartilage is eaten as part of whole animal foods, for example shark fin, gristle on meat and bones used for stock, and it is sold separately as extracts, dried powders and capsules. No ordinary vegetable food contains it. (Source 1)

What happens if you do not have it?

Nothing happens. Not taking cartilage supplements has no known consequence, because there is no deficiency state and the disease claims made for them failed when tested. (Source 7)

How can you test for it?

There is no test of a person's cartilage-supplement status, because there is nothing to measure. What can be tested is the product: laboratory analysis found BMAA in fifteen of sixteen commercial shark cartilage supplements and mercury in all the shark fin products examined. Joint cartilage itself is assessed by imaging, not by a supplement test. (Source 8)

We searched: Searched for cartilage supplement biomarkers and cartilage status tests alongside the NCBI monograph, the CAM-Cancer summary and the two randomised trials; none describes a validated test of an individual's cartilage-supplement status.

References

1. Food and Chemical Toxicology. Environmental neurotoxins β-N-methylamino-l-alanine (BMAA) and mercury in shark cartilage dietary supplements. 2014. PMID 24755394, DOI 10.1016/j.fct.2014.04.015. Read the source
2. CAM-Cancer, NAFKAM, UiT The Arctic University of Norway. Shark cartilage (CAM-Cancer summary): adverse effects and regulatory action. 2023. Read the source
3. National Academies Press / NCBI Bookshelf, in Dietary Supplements: A Framework for Evaluating Safety. Shark Cartilage: Prototype Monograph Summary (composition and contamination). 2005. Read the source
4. Memorial Sloan Kettering Cancer Center. Bovine Cartilage (Integrative Medicine herb monograph): mechanism of action and adverse reactions. 2026. Read the source
5. Journal of Orthopaedic Surgery and Research. Effectiveness and safety of glucosamine and chondroitin for the treatment of osteoarthritis: a meta-analysis of randomized controlled trials. 2018. DOI 10.1186/s13018-018-0871-5. Read the source
6. CAM-Cancer, NAFKAM, UiT The Arctic University of Norway. Shark cartilage (CAM-Cancer summary): abstract and clinical evidence. 2023. Read the source
7. Cancer. Evaluation of shark cartilage in patients with advanced cancer: a North Central Cancer Treatment Group trial. 2005. PMID 15912493, DOI 10.1002/cncr.21107. Read the source
8. National Academies Press / NCBI Bookshelf, in Dietary Supplements: A Framework for Evaluating Safety. Shark Cartilage: Prototype Monograph Summary (adverse effects and evidence quality). 2005. Read the source
9. Memorial Sloan Kettering Cancer Center. Bovine Cartilage (Integrative Medicine herb monograph): overview. 2026. Read the source