Supplement analysis backed by scientific evidence · PT

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Limited evidenceHeart & metabolic

Lumbrokinase

Lumbrokinase is a group of fibrinolytic enzymes from earthworms, used as a prescription-grade drug in China with a real but low-quality trial base in ischemic stroke. Outside that setting it is sold as a supplement for vague 'blood viscosity' and clotting claims that no Western trial supports — and it carries genuine bleeding risk.

What the science says

  • Improves outcomes in acute ischemic stroke Limited evidence

    A 2025 meta-analysis of lumbrokinase in acute ischemic stroke reported improved neurological function scores and acceptable safety, but almost all included trials were conducted in China, were open-label or poorly blinded, and used varied preparations and outcome scales. A multicenter randomized trial in 1,000+ patients found lumbrokinase added to standard therapy reduced fibrinogen and recurrent events, yet methodological limitations and publication concentration in one region keep the evidence grade low.

  • Dissolves clots or 'thins the blood' in healthy people Limited evidence

    No trial has shown that oral lumbrokinase prevents clots, strokes or heart attacks in people without established disease. The supplement marketing extrapolates from in-vitro fibrin plate assays and from stroke trials in already-ill patients, which is not the same thing. Absorption of intact enzyme from the gut is also modest and poorly characterized.

  • Treats long COVID microclots or 'thick blood' Limited evidence

    This is the fastest-growing use and the least supported. The microclot hypothesis remains contested, and no randomized trial of lumbrokinase (alone or in the popular nattokinase-serrapeptase stacks) has tested it in long COVID. Claims of clot dissolution rest on laboratory imaging, not clinical outcomes.

Dosage & safety

Studied doseChinese clinical products are dosed in enzymatic units, typically around 600,000 units three times daily (about 300–400 mg/day of extract) taken on an empty stomach for weeks to months. Western supplements commonly supply 20–40 mg per capsule labeled 300,000–600,000 units, once or twice daily. Unit definitions differ between manufacturers, so label units are not comparable across brands.
SafetyThe central risk is bleeding. Lumbrokinase lowers fibrinogen and degrades fibrin, so combining it with warfarin, DOACs, heparin, aspirin, clopidogrel, high-dose fish oil, or nattokinase meaningfully raises bleeding risk. Stop at least a week before surgery or dental extraction. Avoid in active peptic ulcer, recent hemorrhagic stroke, thrombocytopenia, bleeding disorders, and pregnancy. Reported adverse effects include GI upset, dizziness, rash, and — because it is an animal protein — allergic reactions. Regulatory status matters: it is an approved drug in China but sold as an unregulated supplement in the US and much of Europe, meaning enzyme content is not independently verified. Anyone taking it for a clotting condition should be doing so with a physician, not instead of one.

Scientific references

Where to buy

Dr. Mercola, Lumbrokinase Enzymes, 30 Capsules

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