Papain: Nature’s Own Digestive Aid
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Papain: Nature’s Own Digestive Aid

Image for papain article The papaya (also called papaw, pawpaw, mamao, or tree melon) is believed to have originated in southern Mexico, Central America, or the West Indies, but is now grown in tropical and subtropical areas around the world. It is a pear-shaped fruit with skin that turns from green to a bright orange-yellow as it ripens. It is also the source of one of nature’s own digestive aids: papain.

What is Papain?

Papain is a milky latex that is collected by making incisions in unripe papayas . It is one of a group of proteolytic enzymes found in papayas, pineapples, and certain other plants. Proteolytic enzymes help you digest the proteins in food. Papaya and pineapple stems are two of the richest plant sources of proteolytic enzymes.

Where Does Papain Come From?

Papain comes from the papaya, a tropical fruit that is about 6 inches long and can range from 1-20 pounds in weight, depending on the variety. Inside, the papaya has silky smooth, orange-yellow flesh and a large center cavity full of shiny grayish-black seeds. The flesh is juicy and has a subtle, sweet-tart or musky taste, somewhat like a cantaloupe.

Papaya is now widely cultivated in tropical and subtropical countries. There are about 45 species of papaya. The most common variety in the United States is the Solo papaya, which is grown in Hawaii and Florida. Mexican papayas are much larger than the Hawaiian types and may be more than 15 inches long.

To extract papain latex from a papaya, the skin of an unripe papaya is cut. After the latex is collected, it is dried either by the sun or in ovens and sold in powdered form.

What is Papain Used for?

The primary use of papain is as a meat tenderizer. It is also used as a digestive aid for people who have trouble digesting proteins.

There is weak evidence to suggests that papain, taken in combination with other enzymes, might improve the rate of recovery from various types of injuries and reduce the chronic pain and discomfort of conditions such as neck pain, back pain, shoulder pain, and osteoarthritis. Proteolytic enzymes have also received mixed results as an aid to recovery from surgery and as a treatment for shingles.

Many practitioners of alternative medicine believe that papain may be helpful for food allergies and autoimmune diseases. However, there is little to no meaningful evidence as yet supporting that papain actually works for these conditions.

Some Precautions to Consider

In clinical studies, papain and other proteolytic enzymes are believed to be quite safe, though they may occasionally cause digestive upset and allergic reactions.

If you are taking warfarin, aspirin, or other drugs that thin the blood, you should not take proteolytic enzymes without first discussing it with your doctor.


National Center for Complementary and Alternative Medicine

National Institutes of Health


Canadian Interdisciplinary Network for Complementary and Alternative Medicine Research

Homeopathic Medical Council of Canada


Papaya. University of Florida Extension. Available at: Accessed June 11, 2003.

Papaya: general crop information. Knowledge master. University of Hawaii, Manoa. Available at: Accessed June 11, 2003.

Proteolytic enzymes. EBSCO Health Library, Natural and Alternative Treatments website. Available at:

Last reviewed March 2008 by Richard Glickman-Simon, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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