Individual therapies
Shark cartilage is a food or dietary supplement. It is sometimes used by people as an alternative cancer treatment.
There is not enough reliable evidence that it works as a cure for cancer.
Summary
Shark cartilage comes from spiny dogfish sharks and hammerhead sharks.
Claims that shark cartilage can treat cancer are not backed up by research.
Using shark cartilage as an alternative to conventional cancer treatment can be very harmful to your health.
Cartilage is a tough, flexible tissue found in the body and has no blood supply. Shark cartilage comes from spiny dogfish sharks and hammerhead sharks. It is available as a powder or liquid which you can buy as a food or dietary supplement. There are several different brand names for shark cartilage.
It was once thought that sharks can't get cancer. But this is not true. Sharks can get cancer.
There is no scientific evidence that shark cartilage can control or cure cancer. Some people use shark cartilage as an alternative cancer therapy. This means that they use it instead of conventional cancer treatment such as chemotherapy, targeted drugs or radiotherapy.
This can be very harmful to your health and we do not recommend that you do this.
Read more about why people with cancer use alternative or complementary therapies
Shark cartilage comes in various forms. The most common type is capsules that you swallow.
You can also take it as:
a powder or liquid that you swallow
an enema (a liquid into the back passage)
an injection under the skin
Most researchers agree that the protein molecules in shark cartilage powders are too big for the digestive system to absorb. So shark cartilage that you swallow is not likely to be absorbed into the body.
In the UK, shark cartilage is sold as a food supplement and not a drug. You can buy it over the counter in many health food shops. The USA’s Federal Trade Commission found that many over the counter products don’t actually contain much shark cartilage. Unfortunately, we don’t know how much shark cartilage is in the products available in the UK.
There is no scientifically proven recommended dose of shark cartilage. Some commercial suppliers suggest 70 grams per day. But shark cartilage contains calcium salts, and some doctors are worried this would mean taking in too much calcium. This could cause serious health problems.
We know from research that shark cartilage can often cause changes in the way you taste things.
Other rare side effects include:
feeling and being sick
itching
diarrhoea
constipation
indigestion
dizziness
swelling of the hands and feet due to fluid build up
tiredness
low blood pressure
high blood calcium levels
loss of appetite
change in blood sugar levels
These effects can be serious. Doctors recommend that people with liver disease should not take shark cartilage.
Researchers have been interested in cartilage as a potential treatment for cancer because cartilage doesn’t contain any blood vessels. Cancers develop blood vessels to supply them with food and oxygen and help them to grow. Some laboratory studies have shown that certain compounds in shark cartilage can block the growth of blood vessels. So in theory this could slow down the growth of cancer cells or stop the cancer growing. But no research has shown that it can do this in humans.
A highly purified extract of shark cartilage called Neovastat (AE-941) was tested in a clinical trial in America. They gave Neovastat alongside chemotherapy and radiotherapy to people with advanced lung cancer. Everyone in the trial had chemotherapy and radiotherapy. Half the patients also had treatment with Neovastat. The other patients had a dummy pill (a placebo). The study showed that Neovastat gave few side effects and was safe to take but did not help people to live longer.
Shark cartilage can be quite expensive. Capsules sold over the internet can cost from around £20 for a box of 100 capsules.
Before you start taking it, it is important to consider the ongoing cost.
We do not recommend using alternative therapies such as shark cartilage. This is because there is no scientific or medical evidence to prove that it can treat or cure cancer.
Stopping your conventional cancer treatment to use unproven alternative therapies can be very harmful to your health. Talk to your specialist if you are thinking of taking shark cartilage alongside your cancer treatment. This way, your specialist team will have the full picture about your care and treatment.
Many websites advertise or promote shark cartilage as a cancer treatment. But no reputable scientific cancer organisations support them.
Be very cautious about believing information you read on the internet. Because there isn’t any regulation, people can use the internet to make false claims. Remember that anyone can write information or advertise health treatments.
Learn more about finding reliable information on the web
This page is due for review. We will update this as soon as possible.
Last reviewed: 09 Jun 2022
Next review due: 09 Jun 2025
Find detailed information and research into some of the many different complementary and alternative therapies used by people with cancer.
A balanced and varied diet is the best way to get a healthy supply of vitamins and minerals. Speak to your doctor, specialist nurse or dietitian if you want to take supplements and are having cancer treatment.
A complementary therapy means you can use it alongside your conventional medical treatment. It may help you to feel better and cope better with your cancer and treatment. An alternative therapy is generally used instead of conventional medical treatment.
Treatments can include surgery, radiotherapy and drug treatments (such as chemotherapy, hormone therapy or targeted cancer drugs). Find out about treatments and how to cope with side effects.
Search for the cancer type you want to find out about. Each section has detailed information about symptoms, diagnosis, treatment, research and coping with cancer.
About Cancer generously supported by Dangoor Education since 2010. Learn more about Dangoor Education
What to ask your doctor about clinical trials.
Meet and chat to other cancer people affected by cancer.
Questions about cancer? Call freephone 0808 800 40 40 from 9 to 5 - Monday to Friday. Alternatively, you can email us.
