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Other common name(s): bromelin, bromeline, pineapple enzyme, pineapple extract, Ananase®, Traumanase®, and others

Scientific/medical name(s): sulphydryl proteolytic enzyme, cysteine-proteinase, both made from the plant Ananas comosus


Bromelain is a natural enzyme found in the stem and fruit of the pineapple, a tropical fruit native to Central and South America. Bromelain supplements are promoted as an alternative remedy for various health problems including joint inflammation and cancer.


Some small studies have suggested bromelain may help reduce the ill effects of some types of chemotherapy.

Early studies have also looked at the possible use of bromelain for tissues damaged by burns, as a digestive enzyme, to reduce arthritis pain, and for treating bowel inflammation or diarrhea. However, there are no available scientific studies that have looked at whether bromelain shrinks tumors, improves comfort, or extends the life of people with cancer.

How is it promoted for use?

Proponents claim bromelain reduces the swelling and inflammation of soft-tissue injuries. Some people also believe that the enzyme helps a number of digestive problems. Practitioners claim bromelain relieves the pain and inflammation caused by joint disorders such as arthritis and that it inhibits cancer cell growth when combined with chemotherapy. There are some who claim that bromelain can “digest fat” and that people who take bromelain pills can lose weight without diet or exercise. Some supporters also state that bromelain fights bacterial and viral infections.

What does it involve?

Although small amounts of bromelain can be obtained naturally by eating fresh pineapple, some people also use supplements. They are available in capsules, tablets, and ointments in most health food stores and on the Internet. Bromelain is also a common ingredient in vitamins, enzyme blends, and supplements sold for joint health. Recommended doses vary by manufacturer and use.

What is the history behind it?

Bromelain has been used for hundreds of years in folk medicine as a digestive aid and to treat inflammation and other health problems. Christopher Columbus found pineapples growing on the island of Guadeloupe in 1493 and brought them back to Spain. By the 1600s, they were very popular in Europe. In the sixteenth and seventeenth centuries, the plants were distributed to the Pacific Islands, India, and Africa. Pineapple was first established as a commercial crop in Hawaii in 1885. Recently, bromelain has been investigated for medical uses, including possible anti-cancer activity.

What is the evidence?

There are some suggestions that bromelain may help a number of conditions. However, further research is needed to learn more about bromelain’s possible benefits for humans.

There are studies suggesting that bromelain and other such enzymes may be used with standard cancer treatment to help reduce some side effects (such as mouth and throat inflammation due to radiation treatments). But no available scientific data shows that bromelain affects survival in people who have cancer. More well-controlled research is needed to understand its role, if any, in cancer treatment.

Animal studies suggest that bromelain may help treat diarrhea related to E. coli infections., Lab studies showed bromelain reduced inflammation in cells taken from the intestines of people with inflammatory bowel disease. The health benefits in humans have not been proven.

Because bromelain is an enzyme that breaks down proteins, it may be an alternative to help digestion in people who don’t make enough digestive enzymes on their own. More research is needed to directly compare bromelain to the enzymes generally used for this purpose. Available scientific evidence does not support the idea that bromelain promotes weight loss.

Bromelain also appears to help keep platelets in the blood from sticking together, which in turn may help prevent blood clots. If this is the case, it may also promote bleeding in some people.

Studies on joint pain have also shown mixed results, but bromelain mixed with other enzymes may have an anti-inflammatory effect for those with arthritis. Some clinical trials that compared bromelain and other enzyme mixtures to standard treatment found it less effective, while others reported it as a possible alternative. More research is needed.

Although animal and laboratory studies look promising for some of these uses, further studies are needed to learn whether the results apply to humans.

The German Commission E approved bromelain to be used with other treatments for swelling or inflammation of the nose and sinuses caused by surgery. Some studies have suggested that bromelain may speed recovery time, although not all studies have found it helpful. A 2006 review of 3 studies suggested that bromelain may help relieve the symptoms of sinusitis, although the studies were not of the best quality. And keep in mind that sinusitis caused by allergies or long term infection may respond differently to bromelain.

Are there any possible problems or complications?

This product is sold as a dietary supplement in the United States. Unlike companies that produce drugs (which must be tested before being sold), the companies that make supplements are not required to prove to the Food and Drug Administration that their supplements are safe or effective, as long as they don't claim the supplements can prevent, treat, or cure any specific disease.
Some such products may not contain the amount of the herb or substance that is on the label, and some may include other substances (contaminants). Actual amounts per dose may vary between brands or even between different batches of the same brand. In 2007, the FDA wrote new rules to improve the quality of manufacturing for dietary supplements and the proper listing of supplement ingredients. But these rules do not address the safety of the ingredients or their effects on health.
Most such supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.

Bromelain is generally considered safe. Some people may be allergic to bromelain and pineapple, especially those with allergies to kiwi fruit, papaya (including papain), or natural rubber latex, and serious reactions may occur. Those allergic to honeybee stings, birch or cypress pollen, grass pollen, carrots, celery, fennel, wheat flour, or rye flour may also have a higher risk of reacting to bromelain. People who are allergic to pineapple should not take bromelain.

Upset stomach with nausea, vomiting, and diarrhea have been noted when taking bromelain. A few women have reported increased menstrual bleeding while taking bromelain. Some practitioners advise caution when giving bromelain to people with high blood pressure, liver disease, kidney disease, or bleeding disorders.

When bromelain is taken with blood-thinning medications or aspirin, it may raise the risk of bleeding. Antibiotics in the tetracycline family may reach higher levels in the body when taken with bromelain. There may be other potential interactions between bromelain and medicines or herbs, and some may be dangerous. Always tell your doctor and pharmacist about any herbs you are taking.

Relying on this treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.

Additional resources

More information from your American Cancer Society

The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-ACS-2345).

Dietary Supplements: What Is Safe?

The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management

Complementary and Alternative Methods and Cancer

Placebo Effect

Learning About New Ways to Treat Cancer

Learning About New Ways to Prevent Cancer


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Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.

Last Medical Review: 04/06/2011
Last Revised: 04/06/2011