Lumbrokinase: Benefits, Dosage and Side Effects (Evidence Review)

Lumbrokinase is a group of clot-dissolving enzymes extracted from earthworms. In China it is a prescription drug for stroke patients. In the United States it is sold as a dietary supplement, and it has become a fixture of online protocols for Lyme disease, long COVID, chronic fatigue and "sticky blood," usually with the claim that it is the strongest of the fibrin-dissolving enzymes and breaks down only the fibrin you do not want.

The research behind it is larger than for most supplements and weaker than it first looks. There are dozens of stroke trials, but almost all compared lumbrokinase added to hospital care with hospital care alone, without a placebo. Several placebo-controlled trials were registered but, as far as we can find, never published, and none of the placebo-controlled stroke trials we found has published results. This review walks through what was actually tested, what reaches your blood, where the popular claims come from, what the units on the label mean, and why bleeding is the question that matters most.

What lumbrokinase actually is

Dried earthworm has been used in traditional Chinese medicine for centuries. In 1991, Japanese researchers extracted a set of six protein-digesting enzymes from the earthworm Lumbricus rubellus that could dissolve fibrin, the protein mesh that holds a blood clot together, even on fibrin plates with no plasminogen present. They named the group lumbrokinase. Later work showed the purified enzymes are stable across a very wide range of acidity in the test tube, and that they also activate plasminogen, the body's own clot-dissolving precursor, into plasmin.

That last point matters, because a common marketing line says lumbrokinase does not activate plasminogen and dissolves only abnormal fibrin. The biochemistry says otherwise, and so does the Chinese drug label, which describes the product as containing both a fibrinolytic enzyme and a plasminogen activator and says it lowers fibrinogen, the circulating clotting protein that normal clots are built from.

Regulatory status varies sharply by country. In China, lumbrokinase enteric-coated capsules are approved prescription drugs for people with ischemic cerebrovascular disease and elevated fibrinogen and platelet aggregation. The label we read names the farmed earthworm Eisenia fetida as its source, while supplement marketing usually names Lumbricus rubellus. In Indonesia, a protein fraction called DLBS1033, made by Dexa Medica, is sold as Disolf and registered as an herbal medicine for use alongside standard stroke treatment. In the United States, lumbrokinase is sold as a dietary supplement, and we found no new dietary ingredient notification for it in the FDA's public list. The FDA has, however, treated some lumbrokinase products as unapproved drugs. In 2004 it sent a supplement company a warning letter that cited, among other claims, the statement that research had shown lumbrokinase supports the body in breaking up and dissolving unhealthy coagulation of blood. Since March 2025, its import alert for unapproved new drugs promoted in the United States has listed Boluoke Capsules from Canadian Phytopharmaceuticals, a British Columbia firm, which allows the FDA to detain those shipments without examination; the listing does not name Canada RNA or say which claims prompted it. In Canada, Health Canada refused to license the Boluoke brand as a natural health product in 2006 and again in 2013. Its concern, as the Supreme Court of Canada's case summary and law-firm notes on the 2020 Federal Court ruling describe it, was that healthy people might take it and that the risk of internal bleeding could not be properly monitored when it was sold over the counter. The maker, Canada RNA Biochemical, which proposed it for people it describes as being in hypercoagulable states, says the bleeding concern runs contrary to the available data and that it submitted clinical and safety data. The Federal Court and the Federal Court of Appeal upheld the refusal, and the Supreme Court of Canada declined to hear a further appeal in 2022.

What the evidence actually shows

Nearly all human research on lumbrokinase was done in hospital patients, mostly after a stroke, and mostly without a placebo group. Here is where each common use stands.

Evidence summaries describe research, almost all in hospital patients with diagnosed conditions, and are not claims about what any supplement does for a healthy person.

The stroke trials

The meta-analysis. The largest summary is a 2025 meta-analysis of 35 randomized trials in which lumbrokinase was added to supportive care after an acute ischemic stroke. It reported better scores on two standard measures of stroke recovery. But the trials compared lumbrokinase plus supportive care with supportive care alone and were mostly from China, the reviewers described many as carrying a moderate to high risk of bias, and the results varied so much between trials (heterogeneity of 97 and 94 percent on the two main outcomes) that a single pooled number means little. When the overall response was broken into specific grades, most were not significant. The abstract also reports a pooled change in platelet aggregation of minus 205.86, a figure that is not plausible for a percentage. On disclosure, the published paper declares no conflicts of interest and lists its last author at a university, while a 2024 conference abstract of the same analysis lists him at Dexa Medica, the company that makes DLBS1033.

The individual trials. A 2013 Chinese trial gave 310 patients standard stroke care with or without enteric-coated lumbrokinase for a year. The lumbrokinase group had lower fibrinogen, thinner carotid artery walls, and fewer vascular events (2.08 percent versus 6.78 percent). There was no placebo, blinding was not reported, the groups were of unequal size (192 versus 118), and the authors concluded only that the approach may be beneficial. An earlier randomized, single-blind study of 51 patients with cerebral infarction found lumbrokinase lengthened a clotting time, raised clot-dissolving activity and a marker of clot breakdown, and lowered fibrinogen. Stroke scores fell in both groups, more so with lumbrokinase, but the abstract reports no statistical test for that difference, so it shows an effect on clotting tests more clearly than better recovery.

The only randomized stroke trial of the Indonesian product indexed in PubMed, 180 inpatients published in 2021, was open-label, and one of its authors was a company employee. It reported larger improvements in stroke scores with DLBS1033, but the DLBS1033 group started out more impaired, and by day 30 the two groups' actual scores were nearly identical. The proportion reaching a good functional outcome did not differ significantly (86.7 versus 80 percent). Because the DLBS1033 group started worse, it had more room to improve, so in an open-label trial its larger gains toward a similar day-30 endpoint are hard to credit to the product, although its Barthel score, a measure of daily function, was significantly higher at hospital discharge (14.64 versus 12.12).

The trials that would settle it. A Chinese research team registered a double-blind, placebo-controlled trial of lumbrokinase plus aspirin in 2020, planned for 220 stroke patients; its protocol reported 46 recruited by November 2021. The protocol says lumbrokinase has been widely used for stroke in China, but that because rigorously designed studies are lacking, its safety and efficacy remain largely unknown. We found no results. Placebo-controlled stroke trials of the Indonesian product were stopped early or, as far as we can find, remain unpublished, as described below. A much larger placebo-controlled trial, with bleeding as a co-primary outcome, was registered in 2026 and is not yet recruiting.

What the drug class shows. Chinese researchers describe lumbrokinase as a fibrinogen-depleting agent. A Cochrane review of that class in acute stroke, which included no lumbrokinase trials because none qualified, found eight trials of 5,701 patients testing the related drugs ancrod and defibrase. They slightly reduced death or disability and reduced stroke recurrence, but symptomatic bleeding inside the skull was about twice as common (risk ratio 2.42). The authors judged the evidence not robust enough to support routine use. Lumbrokinase has never been tested in a trial large enough to show whether it shares that trade-off.

Heart, clots and other uses

Chest pain. A 2009 Indonesian pilot gave 10 people with stable angina oral lumbrokinase for 30 days on top of their usual treatment. Scores on a heart perfusion scan improved on average, although they got worse in 3 of the 10, and chest pain improved in 6 of the 10. With no comparison group and 10 patients, the study cannot separate the enzyme from their ongoing treatment or ordinary variation.

Lung clots. A Chinese study of 60 patients with pulmonary embolism compared lumbrokinase added to heparin and warfarin with heparin and warfarin alone. Its English abstract describes the data both as retrospectively analyzed and as randomly divided, while the Chinese abstract says patients were grouped by the treatment they received, so it was most likely not randomized, and it gives no bleeding figures. An Indonesian report described three patients whose clots resolved after catheter treatment followed by lumbrokinase, which cannot show what the enzyme added. All of this is hospital care, and none of it is a reason to treat a clot with a supplement.

Carotid plaque. A Chinese trial of 150 stroke patients added lumbrokinase to a cholesterol drug for a year and reported a better "plaque effective rate" and fewer cerebrovascular events, as P values without effect sizes, with no placebo and no blinding reported. No trial has made plaque regression its main outcome.

Leg artery disease. Two small trials compared DLBS1033 with placebo in people with narrowed leg arteries, one of 20 patients in Jakarta and one of 62, and neither is indexed in PubMed. A 2021 conference abstract that pooled them found only a trend, not statistically significant, toward a better ankle-brachial index, a blood pressure ratio used to gauge leg circulation. A placebo-controlled trial in people with diabetes and leg artery disease enrolled 11 patients before it was stopped for low recruitment.

Healthy people. In the only published placebo-controlled trial of a lumbrokinase product in healthy people, 20 healthy adults took DLBS1033 at 490 milligrams three times a day for 14 days. There were no significant differences from placebo in clotting tests, blood counts, liver or kidney function, cholesterol, blood sugar, stool blood or heart tracings, and no bleeding symptoms. It was a safety study, too small and short to detect uncommon harms, and two of its three authors were affiliated with the manufacturer. An earlier Japanese study gave 7 volunteers whole earthworm powder for 17 days and reported a rise in a clot-dissolving protein, without a control group.

The trials we could not find published

Trial registries record studies before they begin, which makes it possible to see what happened to them. We checked ClinicalTrials.gov for lumbrokinase products and found a pattern worth knowing about. Dexa Medica, which makes DLBS1033, registered seven randomized, placebo-controlled trials of it, one of which was withdrawn before enrolling anyone, and university teams ran two more that have finished. Of the eight that enrolled participants, as far as we can find, only one, the 20-person healthy-volunteer safety study, appears in PubMed.

• Type 2 diabetes, 122 people, completed 2016. A quadruple-masked, placebo-controlled trial of DLBS1033 for two months, with fibrinogen reduction as the main outcome. No results are posted, and we could not find a publication.
• Healthy volunteers, 21 people, completed 2012. A double-masked, placebo-controlled study of clotting measures, run by a university. We could not find a publication.
• Acute stroke, 80 people. Placebo-controlled; terminated in 2023 for very low recruitment.
• Acute stroke, 9 people; diabetic leg artery disease, 11 people; heart attack after stenting, 23 people. All placebo-controlled and terminated early: two for recruitment problems, and the heart attack trial because, in the sponsor's words, the cases "were no longer relevant considering the recent implementation of our current national healthcare system." A trial in another type of heart attack was withdrawn before enrolling anyone, for the same stated reason.
• Acute stroke, 52 people, completed 2025. A double-masked, placebo-controlled trial run by an Indonesian university. It is recent, and we found no publication yet.

Fairness matters here. The stated reasons for stopping were recruitment and relevance, not safety, and unpublished trials are common across medicine. A 126-patient trial comparing DLBS1033 with aspirin and clopidogrel was published, in a journal that PubMed does not index. But the result is that the best-designed studies of lumbrokinase products are the ones readers cannot see, and a supplement's evidence base should be judged on what can actually be checked.

Does it reach your bloodstream?

Lumbrokinase is a set of proteins, and proteins are normally digested. No human study has measured intact lumbrokinase in the blood after swallowing it. The Chinese prescription label says plainly that its human oral pharmacokinetics are not clear.

The absorption evidence comes from animals and lab setups. In pieces of rat intestine held in a laboratory chamber, about 10 to 15 percent of one purified enzyme was absorbed by the intestinal lining, and the authors estimate that about 10 percent of the full-size enzyme could pass through it. The only blood measurements the abstract describes followed injection into the rats' abdomens, not oral dosing. A 2008 formulation study described earthworm fibrinolytic enzyme as having very low oral bioavailability because it is unstable in stomach juice and crosses membranes poorly. Work on DLBS1033 by its manufacturer found it unstable in gastric fluid, which is why products are enteric-coated, and its 70-minute circulation half-life was measured after injecting the enzyme into rat veins, not after an oral dose.

The one human study that tried to track it, in healthy adults taking DLBS1033, did not measure the enzyme at all. It measured a downstream marker of clot breakdown. After a single dose of three tablets taken at once, the marker did not rise (its highest average level was before dosing), and the investigators reported that DLBS1033 activity could not be determined. After three days of repeated dosing, the marker rose, and they calculated a biological half-life of 8.6 hours. That suggests some effect with repeated doses, but it says nothing about how much enzyme gets through. Our enteric coating guide explains why a coating that survives the stomach then opens exactly where the body's own protein-digesting enzymes are released.

Lyme, microclots and other claims

Lyme disease and biofilms. The claim is that lumbrokinase dissolves the fibrin scaffold of Lyme biofilms so antibiotics can reach the bacteria. We found no study of lumbrokinase and the Lyme bacterium of any kind: not in people, not in animals, not in a test tube. A study characterizing Lyme bacterial biofilms in the lab described their matrix as mainly alginate with calcium and extracellular DNA, and did not report fibrin. The closest real evidence is a study of staph biofilms on medical devices, which form on a fibrin matrix. There, nattokinase and other enzymes helped antibiotics clear the biofilm in the lab and, when placed directly into infected catheters, in rats, but lumbrokinase was not tested, nothing was taken by mouth, and staph is not Lyme.

Long COVID and microclots. The idea is that long COVID is driven by tiny clots resistant to normal breakdown, which fibrin-dissolving enzymes could clear. No completed study has tested lumbrokinase in long COVID. In a 2026 lab study of amyloid clots made by repeatedly freezing and thawing pig plasma, lumbrokinase on its own, like nattokinase and the clot-dissolving drug alteplase, did not significantly shrink the clots. Combined with ultrasound, the enzymes added no statistically significant effect at two of three frequencies and a modest one at the third. A Cochrane review found the laboratory evidence insufficient to link these amyloid particles to long COVID, noting they also turn up in healthy people, and a large randomized trial found that the blood thinner rivaroxaban did not significantly improve fatigue in long COVID. The only patient data we found for long COVID come from a survey of 3,925 people with ME/CFS or long COVID, in which nattokinase and lumbrokinase were grouped together and rated favorably compared with the oral vitamin C used as a reference. The ratings were self-reported, there was no placebo group, and the authors note that placebo effects and spontaneous improvement can influence such results. An open-label, non-randomized study at Mount Sinai is now testing lumbrokinase in long COVID, post-treatment Lyme disease syndrome and chronic fatigue syndrome.

Chronic fatigue and "hypercoagulation." The theory that chronic fatigue and fibromyalgia involve low-level clotting activation comes largely from a 1999 paper whose lead author was at HEMEX Laboratories, a commercial lab that offered the related test panel. An independent 2006 study of 17 patients and 16 controls found no significant differences in any clotting measure and concluded that antiplatelet or anticoagulant therapy was not warranted. A 2022 study from the South African group behind the long COVID microclot theory did report more clotting activity, more activated platelets and more microclots in ME/CFS blood than in matched healthy controls, but it tested no treatment, and the Cochrane review discussed above found the laboratory evidence for these particles in long COVID insufficient.

Stronger than nattokinase. The claim that lumbrokinase is 30 times stronger than nattokinase appears in a 2018 Townsend Letter article by a vice-president of Canada RNA, the Boluoke maker, as a milligram-for-milligram comparison of enzyme strength; we found no study behind it, and strength in a lab test says nothing about how much reaches the blood. In a rat study, high-dose nattokinase and an earthworm enzyme used as the comparison showed no difference in clot-breakdown markers. In a rabbit model of stroke, an equally potent dose of lumbrokinase injected directly into the artery reopened the vessel in 1 of 7 animals, the same as saline, while urokinase did so in 6 of 7.

Plaque, blood pressure and cancer. Plaque-reduction claims rest on animal studies and the carotid findings above. We found no study of lumbrokinase with blood pressure as an outcome. Anti-cancer claims come from cell and animal studies, some combining the enzyme with chemotherapy, and we found no human study of cancer outcomes.

Dosage: units, capsules and what trials used

Lumbrokinase labels state potency in units, variously called IU, LKU or U, and those units are not standardized. They come from different laboratory tests and reference standards, so the same material can carry very different numbers: the 1991 paper that named lumbrokinase expressed the activity of its earthworm extract as about 100 plasmin units or 250 urokinase units per gram of earthworm, and the Boluoke supplement label describes one two-capsule serving as both 600,000 IU and 3.2 million tPA activities. Even the six purified enzymes rank in a different order of strength on a casein test than on a fibrin test. We found no international standard for lumbrokinase units, and they cannot be converted to the FU units used for nattokinase.

What prescription labels and trials use. The Chinese prescription label gives 300,000 units per capsule and a dose of 600,000 units, two capsules, three times a day, half an hour before meals, in courses of three to four weeks; it says two to three courses can be taken in a row, or the capsules continued until symptoms improve, or as a doctor directs. Chinese trials that state a dose, such as the carotid plaque trial and the planned double-blind stroke trial described above, used or planned the same 600,000 units three times daily. The Indonesian product was dosed by weight, 490 milligrams three times a day.

What supplements say. Boluoke, a leading brand made in Canada by Canada RNA Biochemical and sold in the US as a dietary supplement, lists 600,000 IU per two-capsule serving and directs one to two capsules one to three times a day on an empty stomach. At the top of that range, that equals the Chinese prescription dose, assuming the units mean the same thing, which we could not confirm. This is a description of labels and trials, not a dosing recommendation.

Side effects, bleeding and interactions

Reported side effects. The Chinese label says a small number of patients have had headache, dizziness, rash, itching, raised eosinophils (a type of white blood cell involved in allergy), and digestive upset such as nausea, vomiting, stomach discomfort, loose stools or constipation. The Canadian maker reports an overall adverse reaction rate of 1.92 percent in a Chinese study of 1,560 patients at 16 hospitals, made up of itching, rash, and nausea or diarrhea, with no bleeding or major side effect reported, figures we could not check against a published paper.

Bleeding. This is the central issue. Lumbrokinase lowers fibrinogen and, in hospital studies, lengthened a clotting time. The 2025 meta-analysis found no statistically significant increase in gastrointestinal bleeding, but that estimate rested on only three trials and was compatible with a substantial increase, and no meta-analysis we found has pooled bleeding in the brain, the complication that matters most after a stroke. In the Indonesian stroke trial, gastrointestinal bleeding occurred in 4 of 90 patients on DLBS1033 and 3 of 90 on standard care. We found no published case report that attributes bleeding to oral lumbrokinase; the closest is a Chinese series of children with lung clots in which a 13-year-old with cancer, given lumbrokinase together with heparin and warfarin or rivaroxaban, had minor bleeding that cannot be pinned on any one drug. For the related drug class in stroke, symptomatic brain bleeding was about twice as common, and a case report describes a brain hemorrhage in a patient who took nattokinase alongside aspirin. The Chinese label says people with acute bleeding should not take lumbrokinase and those prone to bleeding should use it with caution, and Health Canada's refusal to license it rested on the risk of internal bleeding in healthy people who could buy it without a prescription. Its maker, Canada RNA, disputes that view, saying the refusal runs contrary to the available data, including the clinical trial and post-marketing safety data it submitted.

Blood thinners and aspirin. The Chinese label says lumbrokinase strengthens the effect of drugs that inhibit platelets. In animal testing of the Indonesian product, giving it with aspirin or with clopidogrel did not cause stomach lesions, but giving all three together did, which matters for stroke patients prescribed both drugs. Many of the Chinese stroke trials gave it alongside aspirin or clopidogrel, to patients under medical care. The Canadian maker says its Boluoke brand has been shown not to significantly change the PT or aPTT tests, and therefore does not affect INR, the test used to dose warfarin. It adds that other lumbrokinase products may change those tests, tells anyone on prescription drugs to consult a physician first, and says it should be used with strong antiplatelet drugs only under a physician's supervision. For a warfarin user that is still not reassurance: pooled data from Chinese and Indonesian trials showed a small lengthening of aPTT, and a normal INR does not capture fibrin breakdown. No study has measured the bleeding risk of combining lumbrokinase with warfarin or the newer anticoagulants; the small Chinese study that added it to heparin and warfarin for lung clots gives no bleeding figures in its abstract.

Surgery. The Canadian maker calls stopping one week before surgery the conservative approach, and says it can be resumed 15 days afterward if there are no complications, or sooner if the physician agrees. A more cautious approach, which our ingredient page follows, is to stop at least one to two weeks before any planned operation, dental extraction or injection procedure. Tell your surgeon, anesthesiologist or dentist if you take it.

Allergy and contamination. We found no published case report of an allergic reaction to oral lumbrokinase, though the Chinese label lists rash, itching and raised eosinophils among its side effects and says anyone allergic to the product must not take it. Allergy to earthworms themselves is documented, including a fisherman who developed swelling, rhinitis and asthma from handling Eisenia fetida bait, the species named on the Chinese label. Earthworms also concentrate heavy metals from soil: a Chinese analysis of 98 batches of dried earthworm used in traditional medicine estimated, in a consumption model, arsenic and chromium risks above levels the US EPA considers acceptable. That work concerns crude earthworm, not purified capsules, which we found no independent testing for.

Pregnancy and children. There are no human safety data. In animal testing of the Indonesian product, researchers found no adverse effect on prenatal development at a moderate dose but advised caution at high doses in pregnancy, and the Canadian maker reports mouse studies of its own product that found no birth defects, which we could not check against a published paper. The Chinese label advises caution in pregnancy and breastfeeding because there are no studies in pregnant or breastfeeding women and it is unknown whether the enzyme crosses the placenta or into milk, and says safety in children has not been established.

How it compares with other enzymes

Lumbrokinase is the most drug-like of the systemic enzymes: a prescription medicine in China, with far more stroke trials than any rival, almost all of them in hospital patients and almost none placebo-controlled. Nattokinase has smaller but better-controlled trials and a modest blood pressure signal, roughly 3 mmHg systolic, which our nattokinase review covers, while its best-designed long-term trial in healthy adults found no effect on artery thickness. Serrapeptase has the weakest record of the group, and the larger trials run by its original maker missed their main goals, as we explain in does serrapeptase work. Bromelain, reviewed in our bromelain evidence review, is the best characterized for absorption and has a small pain benefit after dental surgery, but it is not sold as a clot dissolver. None of the four has a trial showing a meaningful health benefit in people without a diagnosed condition. If you are weighing any of them alongside medication, our guide to supplement and drug interactions covers the blood thinner questions to ask.

Frequently asked questions

What is lumbrokinase used for?

In China, lumbrokinase enteric-coated capsules are prescription drugs for people with ischemic cerebrovascular disease and high fibrinogen and platelet aggregation, and nearly all human research was done in hospital patients after a stroke. In the United States it is sold as a dietary supplement, often promoted for circulation, Lyme disease, long COVID and chronic fatigue. None of those supplement uses has a completed controlled trial behind it, and the only published placebo-controlled study in healthy people found no significant difference from placebo in clotting measures.

Does lumbrokinase dissolve blood clots in people?

It changes clotting measurements. In hospital studies it lowered fibrinogen and lengthened a clotting time, and one study found higher markers of clot breakdown. Whether that dissolves clots and improves outcomes is not established. The stroke trials compared lumbrokinase added to standard care with standard care alone, mostly without a placebo, and in a rabbit model an equally potent dose injected into the artery cleared a brain clot in only one of seven animals, the same as saline. Anyone with a known or suspected clot needs medical treatment, not a supplement.

Is lumbrokinase safe?

Its safety has not been established. It is designed to break down fibrin, so bleeding is the main concern. Pooled stroke data were too thin to rule out extra gastrointestinal bleeding, and no meta-analysis we found has pooled bleeding in the brain. Health Canada declined to license the leading brand as a natural health product, citing the risk of internal bleeding in people buying it without supervision; the maker disputes that assessment, and Canadian courts upheld the decision. The Chinese prescription label says people with acute bleeding should not take it and people prone to bleeding should use it with caution.

Can I take lumbrokinase with blood thinners or aspirin?

Not without your prescriber's agreement. The Chinese prescription label says it strengthens the effect of drugs that inhibit platelets, and hospital studies show it lowers fibrinogen and lengthens a clotting time. The Canadian maker says its product has been shown not to significantly affect the PT or aPTT tests, and so not the INR used to monitor warfarin; it notes that other lumbrokinase products may, and advises checking with a physician first. Those tests do not capture fibrin breakdown, so a normal INR does not mean the combination is safe, and no study has measured the bleeding risk of combining it with warfarin or the newer anticoagulants.

How much lumbrokinase do people take?

The Chinese prescription label we read gives 600,000 units, as two 300,000-unit capsules, three times a day half an hour before meals, in courses of three to four weeks, and allows two to three courses in a row. Boluoke, a leading brand made in Canada and sold in the US as a supplement, lists 600,000 IU per two-capsule serving with directions of one to two capsules one to three times a day on an empty stomach, so on paper its upper range matches the prescription dose. The Indonesian product was dosed by weight, 490 milligrams three times a day. Units are not standardized between products and cannot be converted to the FU units used for nattokinase. This is a description of what products and trials use, not a dosing recommendation.

Does lumbrokinase help long COVID or Lyme disease?

No completed study has tested it for either. We found no study of lumbrokinase and the Lyme bacterium at all. For long COVID, the evidence is a patient survey that grouped lumbrokinase with nattokinase, used vitamin C rather than a placebo as its reference, and relied on self-report, plus a lab study in which lumbrokinase on its own did not significantly break down amyloid clots made from pig plasma and added a significant effect beyond ultrasound at only one of three settings. The microclot idea itself is disputed, and an anticoagulant trial in long COVID found no significant benefit for fatigue. A small open-label study at Mount Sinai is recruiting.

Is lumbrokinase stronger than nattokinase or serrapeptase?

We found no human head-to-head comparison. The claim that it is 30 times stronger than nattokinase appears in a 2018 article by a vice-president of Canada RNA, the Boluoke maker, as a milligram-for-milligram comparison of enzyme strength; we found no study behind it, and in a rat study high-dose nattokinase and an earthworm enzyme showed no difference in markers of clot breakdown. The claim that it dissolves only abnormal fibrin is also unsupported: the purified enzymes activate plasminogen and break down fibrinogen, and in patients it lowers normal circulating fibrinogen.

Is lumbrokinase vegan?

No. It is extracted from earthworms. Supplement marketing usually names the species Lumbricus rubellus, while the Chinese prescription label we read names the farmed earthworm Eisenia fetida. People who avoid animal products, or who follow religious dietary rules, may want to avoid it.

The bottom line

Lumbrokinase is a real clot-active enzyme with a real clinical history, as a prescription drug for stroke patients in China. That history is also its limitation. The trials mostly added it to hospital care without a placebo and varied widely, none of the placebo-controlled stroke trials we found has published results, and several placebo-controlled trials of the Indonesian product are, as far as we can find, unpublished. In healthy people, the one published placebo trial found no significant difference from placebo in clotting or routine safety tests. The claims that drive its supplement sales, dissolving Lyme biofilms and long COVID microclots, have no human study behind them. What is well documented is that it lowers fibrinogen and changes clotting tests, and Health Canada declined to license the leading brand over the risk of internal bleeding. If you are considering it, treat it as the drug it is elsewhere: talk to your clinician first, never combine it with blood thinners on your own, and stop it before any procedure.