Nov 3, 2026
Swallowing proteolytic enzymes on an empty stomach is unlikely to clear dead tissue, scar tissue or “excess fibrin” from your body. Enzymes do remove dead tissue very well when a clinician applies them directly to a wound or burn. Taken by mouth, the best evidence supports something narrower: modest relief of swelling and pain after some surgeries.
Supplement labels and wellness sites often promise that oral enzymes “eat away” scar tissue, dissolve arterial plaque or digest dead cells. Here is what the research supports, what it does not, and who should avoid these products.
What are proteolytic enzymes?
Proteolytic enzymes, also called proteases, are enzymes that cut proteins into smaller pieces. Your pancreas makes its own, such as trypsin and chymotrypsin, to digest the protein in your food. The supplements sold for “systemic” use come from plants, bacteria or animals:
- Bromelain: a mix of enzymes from pineapple stems.
- Papain: from papaya.
- Serrapeptase (serratiopeptidase): made by Serratia bacteria originally isolated from silkworms.
- Nattokinase: from natto, a fermented soybean food.
- Trypsin and chymotrypsin: usually from animal pancreas.
- Blends: products such as Wobenzym combine several of these, often with the plant compound rutin.
Taken with meals, these products work as digestive aids. Taken between meals, the claim is that they enter the bloodstream and act on inflammation, clots and damaged tissue throughout the body. That second claim is the subject of this article. For broader context on supplement evidence, see our guide to anti-aging dietary supplements.
Why “take on an empty stomach” — and why it may not matter much
The empty-stomach advice makes sense on its own terms, but very little enzyme reaches your blood either way. The idea is that without a meal to digest, more of the dose stays free to be absorbed. Many products are also enteric-coated, because stomach acid can destroy enzymes such as serrapeptase before they reach the small intestine, as Rajaram and colleagues note in the Journal of Clinical and Diagnostic Research.
The best human data come from bromelain. In a 1997 study in the American Journal of Physiology, volunteers took about 3 grams a day, a far larger dose than most supplements. Intact bromelain did appear in their blood, but at only about 5 nanograms per milliliter after two days.
What does get through is quickly captured. The same study found circulating bromelain bound to alpha-2-macroglobulin, a blood protein whose job is to trap stray protein-cutting enzymes. A 2002 study in Clinical Immunology showed that plasma, and purified alpha-2-macroglobulin, sharply blocked bromelain’s activity. The authors concluded that any enzyme concentrations high enough to matter are more likely reached in the gut than in tissues elsewhere in the body.
Where enzymes really do remove dead tissue
Enzymatic debridement, the removal of dead tissue with enzymes, is real medicine when the enzyme is applied directly to the wound. The clearest example is NexoBrid, a concentrate of bromelain enzymes from pineapple stems. A 2024 review of bromelain in burn care describes how it dissolves eschar, the dead crust that forms on deep burns, with less risk of cutting away healthy tissue than surgery. The European Medicines Agency approved it in 2012, and the U.S. Food and Drug Administration (FDA) followed in 2022.
The contrast with supplements is concentration and contact. A burn treatment bathes dead tissue in a large dose of enzyme for hours. A capsule delivers trace amounts to the blood, where your body neutralizes them. Inside the body, your own immune cells already do the cleanup: white blood cells called neutrophils and macrophages break down and remove dead tissue as part of normal healing.
What the evidence for oral enzymes shows
The best oral evidence is for modest relief of pain and swelling after surgery or with arthritis, not for clearing dead or scarred tissue. We found no randomized controlled trials (RCTs) showing that swallowed enzymes remove scar tissue, adhesions or dead tissue in people.
| Claim | Best evidence | What it found |
|---|---|---|
| Clears dead tissue, scar tissue or adhesions | No human RCTs found | Unsupported |
| Serrapeptase for inflammation, pain or heart health | Bhagat et al., 2013 systematic review | Evidence insufficient to support use as a pain reliever or health supplement; long-term safety data lacking |
| Serrapeptase after wisdom tooth removal | Sivaramakrishnan and Sridharan, 2018 meta-analysis of 5 studies | Improved jaw stiffness and facial swelling; small evidence base |
| Bromelain after wisdom tooth removal | 2019 meta-analysis in the Journal of Oral and Maxillofacial Surgery of 6 RCTs | Less swelling (larger effect by day 7) and less pain at day 7; no effect on jaw stiffness |
| Bromelain after wisdom tooth removal | Mendes et al., 2019 meta-analysis of 6 RCTs | Less pain and better quality of life; no clear effect on swelling |
| Enzyme blend (Wobenzym) for knee osteoarthritis | Bolten et al., 2015 RCT, 150 adults, 12 weeks | Similar to the nonsteroidal anti-inflammatory drug (NSAID) diclofenac on the main pain score; on a second score, only diclofenac beat placebo |
Two patterns stand out. First, even the positive findings are about swelling and pain, which fits an anti-inflammatory effect rather than tissue removal. Second, two meta-analyses of bromelain after the same surgery reached different conclusions about swelling, a sign of how small and variable these trials are.
Safety: who should be careful
The main risk is bleeding, because several of these enzymes break down fibrin, the protein that holds blood clots together. Most side effects are mild, but the rare serious ones are worth knowing.
- Bleeding. A published case report describes an older woman with atrial fibrillation who took over-the-counter nattokinase, developed severe internal bleeding and died. Talk to your doctor before combining any of these enzymes with blood thinners, aspirin or other antiplatelet drugs, and tell your surgeon you take them before any procedure.
- Spreading infection. Because serrapeptase breaks down fibrin, it may weaken the barrier the body builds around an infection. Rajaram and colleagues reported a dental abscess that appeared to spread into deeper tissue of the face after serrapeptase was given.
- Lung inflammation. Japanese case reports describe serrapeptase-induced pneumonitis and eosinophilic pneumonia, which improved once the drug was stopped. These are rare.
- Allergy. People allergic to pineapple, papaya or natto (fermented soybeans) should avoid the matching enzyme.
- Digestive upset. Nausea, loose stools and stomach discomfort are the most common complaints.
The Keep.Health take
Skip oral proteolytic enzymes if your goal is to remove dead tissue, scar tissue or “clogged” arteries. The idea is appealing, but too little enzyme reaches your tissues, and no human trials show the effect.
A narrower case holds up better. If you want help with swelling and pain after an injury or minor surgery, bromelain has the most consistent, if modest, support. Clear it with your surgeon first, especially if you take any blood thinner. For more on healing well, see our guide to injury recovery time by age.
If you have a wound with black, yellow or gray dead tissue, see a clinician. Wound debridement is a medical procedure, and a capsule is not a substitute.
