Papain is an enzyme (a molecule that speeds up a chemical reaction) found in the latex produced by the fruit of the papaya plant (Carica papaya). The release of this enzyme-rich latex may be part of the plant's defense mechanism and aids in cleaning and sealing the damaged areas of the plant.
In some parts of Africa, papain is used to treat burn wounds, especially in children, and to stimulate healing. In standard Western medical care, papain-containing agents are commonly used to remove dead tissue from burns and many types of wounds and skin ulcers. Traditionally, papain has also been used as digestive aid. Today, papain remains a popular after-meal supplement.
Allergic sensitivity to papain may cause symptoms ranging from itchiness to abdominal cramps, diarrhea, and excessive sweating. Papain is used as a meat tenderizer and in processing beer, so symptoms may occur after ingestion of foods seemingly unrelated to papain.

Related Terms

Actinidin, aleurain, bromelain, Carica papaya, caricain, cathepsin B, cathepsin C, cathepsin H, cathepsin K, cathepsin L, cathepsin S, chymopapain, ficin, human cysteine proteases, meat tenderizer, papain-like enzyme, papaya, papaya enzyme, proteolytic enzymes.
Combination product examples: Prosta-Q (quercetin, saw palmetto, cranberry, bromelain, papain, zinc), Wobenzym® (pancreatin, bromelain, papain, lipase, amylase, trypsin, alpha chymotrypsin, rutin).

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Exercise recovery (Grade: C)
Research suggests that a combination product containing papain may speed muscle recovery and reduce soreness in runners. Additional research on the effects of papain alone is needed.
Gastrointestinal disorders (phytobezoar) (Grade: C)
Papain may be useful in the treatment of phytobezoars (masses of partially digested or undigested plant material in the gastrointestinal tract). Papain treatment may also damage the esophagus and stomach. More research is needed to determine if papain can be useful while avoiding these adverse effects.
Jellyfish stings (Grade: C)
Limited research has investigated the treatment of jellyfish stings with papain. Additional research is needed in this area.
Lung conditions (lung abscess) (Grade: C)
Research suggests that papain may be useful in the treatment of lung abscesses when used together with other therapies. Additional research is needed in this area.
Radiation therapy side effects (Grade: C)
Limited research on the use of papain to reduce the negative side effects of radiation therapy has shown mixed results. Additional research is needed before a conclusion can be made.
Recovery from surgery (prevention of postoperative adhesion formation) (Grade: C)
Papain and other enzymes have been used to prevent postoperative adhesions. Additional research is needed in this area.
Rheumatic disorders (Grade: C)
Limited research suggests that papain and other protein-digesting enzymes may reduce pain and inflammation in rheumatic disorders.
Skin conditions (xerotic skin) (Grade: C)
Papain has shown some benefits in reducing scaling of xerotic (excessively dry) skin. More high-quality studies are needed in this area before a conclusion can be made.
Sore throat (Grade: C)
Papain has shown some benefits in reducing the symptoms of pharyngitis and tonsillitis. More high-quality studies are needed before a conclusion can be made.
Wound healing (Grade: C)
Studies suggest that papain may be very useful for removing dead tissue from wounds and stimulating healing. More high-quality research is needed in this area.
Insect bites (fire ants) (Grade: D)
Limited research exploring the treatment of fire ant bites with papain found a lack of benefit. Additional research is needed in this area.