Bromelain is not actually a single substance, but rather a collection of protein-digesting enzymes (also called proteolytic enzymes) found in pineapple juice and in the stem of pineapple plants. It is primarily produced in Japan, Hawaii, and Taiwan, and much of the original research was performed in the first two of those locations. Subsequently, European researchers developed an interest, and, by 1995, bromelain had become the thirteenth most common individual herbal product sold in Germany.
Other proposed uses of bromelain include chronic venous insufficiency (closely related to varicose veins), hemorrhoids, other diseases of the veins, bruising, rheumatoid arthritis, gout, ulcerative colitis,1 and dysmenorrhea (menstrual pain). However, there is no real evidence that bromelain is effective for these conditions. One study failed to find bromelain effective for osteoarthritis.49
Bromelain is definitely useful as a digestive enzyme. Unlike most digestive enzymes, bromelain is active both in the acid environment of the stomach and the alkaline environment of the small intestine.2,3 This may make it particularly effective as an oral digestive aid for those who do not digest food properly.4,5,6
Bromelain may also increase the absorption of various drugs, particularly antibiotics such as amoxicillin and tetracycline. This could offer both risks and benefits.7-10
Bromelain is widely available in groceries as a meat tenderizer.
While most large enzymes are broken down in the digestive tract, those found in bromelain appear to be absorbed whole to a certain extent.11-13 This finding makes it reasonable to suppose that bromelain can actually produce systemic (whole body) effects. Once in the blood, bromelain appears to reduce inflammation, "thin" the blood, and affect the immune system.14-30,43,44 These influences may be responsible for some of bromelain's therapeutic effects.
See also Proteolytic Enzymes for a discussion of combination products that often contain bromelain.
The evidence for bromelain as a treatment for injuries and surgeries is mixed.
A double-blind, placebo-controlled study evaluated 160 women who received episiotomies (surgical cuts in the perineum) during childbirth.31 Participants given 40 mg of bromelain 4 times daily for 3 days, beginning 4 hours after delivery, showed a statistically significant decrease in edema, inflammation, and pain. Ninety percent of patients taking bromelain demonstrated excellent or good responses compared to 44% in the placebo group. However, another double-blind study of 158 women who received episiotomies failed to find significant benefit.32
In a double-blind controlled trial, 95 patients undergoing treatment for cataracts were given 40 mg of bromelain or placebo (along with other treatments) 4 times daily for 2 days prior to surgery and 5 days post-operatively.33 Overall, less inflammation was noted in the bromelain-treated group compared to the placebo group.
A somewhat informal controlled study of 146 boxers suggested that bromelain helps bruises to heal more quickly.36 Another study—this one without any type of control group—found that bromelain reduced swelling, pain at rest, and tenderness among 59 patients with blunt trauma injuries, including bruising.37
People who engage in intense exercise to which they are not accustomed may experience a set of symptoms called delayed onset muscle soreness (DOMS), consisting of pain, reduced flexibility, and weakness of the muscles involved. Bromelain has been proposed for this condition, but a small double-blind, placebo-controlled study failed to find it effective.48
In a double-blind trial, 48 patients with moderately severe to severe sinusitis received bromelain or placebo for 6 days.38 All patients were placed on standard therapy for sinusitis, which included antihistamines, analgesics, and antibiotics. Upon completion of the study, inflammation was reduced in 83% of those taking bromelain compared to 52% of the placebo group. Breathing difficulty was relieved in 78% of the bromelain group and 68% of the placebo group. Overall, good to excellent results were observed in 87% of patients treated with bromelain compared to 68% on placebo.
Benefits were also seen in two other studies enrolling a total of more than 100 individuals with sinusitis.39,40
Recommended dosages of bromelain vary with the form used. Due to the wide variation, we suggest following label instructions.
Bromelain appears to be essentially nontoxic, and it seldom causes side effects other than occasional mild gastrointestinal distress or allergic reactions.41
However, because bromelain "thins" the blood to some extent, it shouldn't be combined with drugs such as warfarin (Coumadin) without a doctor's supervision.
According to one small animal study, bromelain might interact with sedative medications, increasing their effect.42 As noted above, it might also increase blood levels of various antibiotics, which could present risks in some cases. In addition, one trial suggests that doses of bromelain eight times higher than standard recommendations might increase heart rate (but not blood pressure).47
Safety in young children, pregnant or nursing women, or those with liver or kidney disease has not been established.
Kane S, Goldberg MJ. Use of bromelain for mild ulcerative colitis [letter]. Ann Intern Med. 2000;132:680.
Taussig SJ, Yokoyama MM, Chinen A, et al. Bromelain, a proteolytic enzyme and its clinical application. A review. Hiroshima J Med Sci. 1975;24:185-193.
Taussig SJ, Batkin S. Bromelain, the enzyme complex of pineapple ( Ananas comosus) and its clinical application. An update. J Ethnopharmacol. 1988;22:191-203.
Moshal MG. Nutrizym as a pancreatic enzyme replacement. S Afr Med J. 1974;48:1489-1490.
Knill-Jones RP, Pearce H, Batten J, et al. Comparative trial of Nutrizym in chronic pancreatic insufficiency. Br Med J. 1970;4:21-24.
Goodchild MC, Sagaro E, Brown GA, et al. Comparative trial of pancrex V forte and nutrizym in treatment of malabsorption in cystic fibrosis. Br Med J. 1974;3:712-714.
Moss JN, Frazier CV, Martin GJ. Bromelains. The pharmacology of the enzymes. Arch Int Pharmacodyn Ther. 1963;145:166-188.
Tinozzi S, Venegoni A. Effect of bromelain on serum and tissue levels of amoxycillin. DrugsExp Clin Res. 1978;4:39-44.
Luerti M, Vignali M. Influence of bromelain on penetration of antibiotics in uterus, salpinx and ovary. Drugs Exp Clin Res. 1978;4:45-48.
Mori S, Ojima Y, Hirose T, et al. The clinical effect of proteolytic enzyme containing bromelain and trypsin on urinary tract infection evaluated by double blind method. Acta Obstet Gynaecol Jpn. 1972;19:147-153.
Smyth RD, Brennan R, Martin GJ. Studies establishing the absorption of bromelains (proteolytic enzymes) from the gastrointestinal tract. Exp Med Surg. 1964;22: 46-59.
Miller JM, Ginseberg M, McElfatrick GC, et al. The administration of bromelain orally in the treatment of inflammation and edema. Exp Med Surg. 1964;22:293-299.
Castell JV, Friedrich G, Kuhn CS, et al. Intestinal absorption of undegraded proteins in men: presence of bromelain in plasma after oral intake. Am J Physiol. 1997;273:G139-G146.
Izaka KI, Yamada M, Kawano T. Gastrointestinal absorption and antiinflammatory effect of bromelain. Jpn J Pharmacol. 1972;22:519-534.
Seligman B. Bromelain: an anti-inflammatory agent. Angiology. 1962;13:508-510.
Seligman B. Oral bromelains as adjuncts in the treatment of acute thrombophlebitis. Angiology. 1969;20:22-26.
Pirotta F, De Giuli-Morghen C. Bromelain—a deeper pharmacological study. Note I. Antiinflammatory and serum fibrinolytic activity after oral administration in the rat. Drugs Exp Clin Res. 1978;4:1-20.
Smyth RD, Brennan R, Martin GJ. Systemic biochemical changes following the oral administration of a proteolytic enzyme, bromelain. Arch Int Pharmacodyn Ther. 1962;136:230-236.
Livio M. Effect of bromelain on fibrinogen level, prothrombin complex factors and platelet aggregation in the rat. Drugs Exp Clin Res. 1978;4:49-53.
Opher AW, Miller JM. The enzymatic properties of bromelain. Exp Med Surg. 1964;22:281-292.
Didisheim P, Lewis JH. Fibrinolytic and coagulant activities of certain snake venoms and proteases. Proc Soc Exp Biol Med. 1956;93:10-13.
Vellini M, Desideri D, Milanese A, et al. Possible involvement of eicosanoids in the pharmacological action of bromelain. Arzneimittelforschung. 1986;36:110-112.
Metzig C, Grabowska E, Eckert K, et al. Bromelain proteases reduce human platelet aggregation in vitro, adhesion to bovine endothelial cells and thrombus formation in rat vessels in vivo. In Vivo. 1999;13:7-12.
Heinicke RM, Wal L van der, Yokoyama M. Effect of bromelain (Ananase) on human platelet aggregation. Experientia. 1972;28: 844-845.
Taussig SJ, Batkin S. Bromelain, the enzyme complex of pineapple (Ananas comosus) and its clinical application. An update. J Ethnopharmacol. 1988;22:191-203.
Felton GE. Fibrinolytic and antithrombotic action of bromelain may eliminate thrombosis in heart patients. Med Hypotheses. 1980;6:1123-1133.
Bodi T. Modifications of tissue permeability by orally administered proteolytic enzymes in man. Exp Med Surg. 1965;(suppl):51-62.
Lotz-Winter H. On the pharmacology of bromelain: an update with special regard to animal studies on dose-dependent effects. Planta Med. 1990;56:249-253.
Kumakura S, Yamashita M, Tsurufuji S. Effect of bromelain on kaolin-induced inflammation in rats. Eur J Pharmacol. 1988;150:295-301.
Barrett AJ, Starkey PM. The interaction of alpha 2-macroglobulin with proteinases. Characteristics and specificity of the reaction, and a hypothesis concerning its molecular mechanism. Biochem J. 1973;133:709-724.
Zatuchni GI, Colombi DJ. Bromelains therapy for the prevention of episiotomy pain. Obstet Gynecol. 1967;29:275-278.
Howat RC, Lewis GD. The effect of bromelain therapy on episiotomy wounds—a double-blind controlled clinical trial. J Obstet Gynaecol Br Commonw. 1972;79:951-953.
Spaeth GL. The effect of bromelains on the inflammatory response caused by cataract extraction: a double-blind study. Eye Ear Nose Throat Mon. 1968;47:634-639.
Tassman GC, Zafran JN, Zayon GM. Evaluation of a plant proteolytic enzyme for the control of imflammation and pain. J Dent Med. 1964;19:73-77.
Gylling U, Rintala A, Taipale S, et al. The effect of a proteolytic enzyme combinate (bromelain) on the postoperative oedema by oral application. A clinical and experimental study. Acta Chir Scand. 1966;131:193-196.
Blonstein JL. Control of swelling in boxing injuries. Practitioner. 1969;203:206.
Masson M. Bromelain in blunt injuries of the locomotor system. A study of observed applications in general practice [in German; English abstract]. Fortschr Med. 1995;113:303-306.
Ryan RE. A double-blind clinical evaluation of bromelains in the treatment of acute sinusitis. Headache. 1967;7:13-17.
Taub SJ. The use of ananase in sinusitis: A study of 60 patients. Eye Ear Nose Throat Mon. 1966;45:96,98.
Seltzer AP. Adjunctive use of bromelains in sinusitis: a controlled study. Eye Ear Nose Throat Mon. 1967;46:1281-1288.
Blumenthal M, ed. The Complete German Commission E Monographs, Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications; 1998:94.
Moss JN, Frazier CV, Martin GJ. Bromelains. The pharmacology of the enzymes. Arch Int Pharmacodyn Ther. 1963;145:166-188.
Brakebusch M, Wintergerst U, Petropoulou T, et al. Bromelain is an accelerator of phagocytosis, respiratory burst and killing of Candida albicans by human granulocytes and monocytes. Eur J Med Res. 2001;6:193-200.
Desser L, Rehberger A, Paukovits W. Proteolytic enzymes and amylase induce cytokine production in human peripheral blood mononuclear cells in vitro. Cancer Biother. 1994;9:253-263.
Seltzer AP. Minimizing post-operative edema and ecchymoses by the use of an oral enzyme preparation (bromelain): a controlled study of 53 rhinoplasty cases. Eye Ear Nose Throat Mon. 1962;41:813-817.
Frank SC. Use of chymoral as an anti-inflammatory agent following surgical trauma. J Am Podiatr Assoc. 1965;55:706-709.
Gutfreund A, Effect of oral bromelain on blood pressure and heart rate of hypertensive patients. Hawaii Medical Journal 1978;37:143-146
Stone MB, Merrick MA, Ingersoll CD, et al. Preliminary comparison of bromelain and ibuprofen for Delayed Onset Muscle Soreness management. Clin J Sport Med. 2002;12:373-378.
Brien S, Lewith G, Walker AF, et al. Bromelain as an adjunctive treatment for moderate-to-severe osteoarthritis of the knee: a randomized placebo-controlled pilot study. QJM. 2006;99:841-850.
Last reviewed December 2015 by EBSCO CAM Review Board
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.