Microclots are significant in the pathology of my post-viral fatigue syndrome (which is equivalent to ME, according to the Canadian Consensus Criterion).


Anti-thrombotic/proteolytic enzyme therapy as both test and treatment.

1 month of:

  • enteric Nattokinase, 2,000 FU, daily–first thing in the morning, empty stomach, plenty of water
  • enteric Serrapeptase, 40,000 SPU, daily–first thing in the morning, empty stomach, plenty of water
Natto-Serra front Natto-Serra back
Doctor's Best Natto-Serra

An affirmative result will be indicated by palpably-reduced post-exertional malaise, and/or a palpable and sustained increase in my energy envelope.



Background Research

Kell et al’s papers on microclots in Long COVID (Kell & Pretorius, 2022) and ME/CFS (Nunes et al., 2022) report that blood samples from patients are hypercoagulable, and contain, on average, around 10 times as many microclots compared to age-matched healthy controls.

Ben Coomber’s recovery cites use of Nattokinase, Lumbrokinase and Serrapeptase for a month–these are off-the-shelf anti-thrombotic (anti-clotting) proteolytic (protein degrading) enzymes.

Many Long COVID patients reported on their experience using these clot-busting enzymes to @organichemusic on Twitter. This survey has shown that the treatment is effective for PEM and other symptoms in a large proportion of respondents (around half, 50%).


Clinically, when clotting pathology is suspected, a blood test for the level of D-dimer is carried out. High levels of D-dimer indicate that regular blood clots are being broken down in the body and therefore doesn’t tell you anything about the level of microclots. I happen to know my D-dimer is normal as I was tested for it in July during a hospital visit for suspected deep vein thrombosis–it turned out to be cellulitis from a mosquito bite, which I got again a month later.

Specialized fluorescence microscopy is required to detect microclots. Many people with Long COVID have traveled to Dr Beate Jaeger’s lab in Mühlheim, Germany. Anecdotally the test costs around 500EUR, plus travel and accommodation.


The benefit of any of these may only be temporary.

Anti-thrombotic/proteolytic enzyme risk profile

The enzymes are available without a prescription, and so presumably meet consumer standards for quality and safety.

Serrapeptase is mucolytic (Sharma et al., 2021), so may irritate or damage the gut lining–this seems potentially counterproductive.

A survey of 84 Long COVID sufferers published on Twitter by @organichemusic showed:

  • Nattokinase/Lumbrokinase plus Serrapeptase resulted in improvement in post-exertional malaise in over 50% of respondents taking the combination (around half of respondents, 38 people).
  • Of those taking the combination, 2 got slightly worse 5%.
  • 5 of 84 reported increased bleeding of different kinds.

Apheresis risk profile

All the risks that go along with visiting a hospital abroad to get your blood filtered.


  1. Kell, D. B., & Pretorius, E. (2022). The potential role of ischaemia–reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications. Biochemical Journal, 479(16), 1653–1708. https://doi.org/10.1042/BCJ20220154
  2. Nunes, J. M., Kruger, A., Proal, A., Kell, D. B., & Pretorius, E. (2022). The Occurrence of Hyperactivated Platelets and Fibrinaloid Microclots in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Pharmaceuticals, 15(8), 931. https://doi.org/10.3390/ph15080931
  3. Sharma, C., Jha, N. K., Meeran, M. F. N., Patil, C. R., Goyal, S. N., & Ojha, S. (2021). Serratiopeptidase, A Serine Protease Anti-Inflammatory, Fibrinolytic, and Mucolytic Drug, Can Be a Useful Adjuvant for Management in COVID-19. Frontiers in Pharmacology, 12. https://doi.org/10.3389/fphar.2021.603997

Treatment log

Date Treatment Perceived reaction
2022-10-20 Dr’s Best Natto/Serra, 1 cap on rising None
2022-10-21 Dr’s Best Natto/Serra, 1 cap on rising Bloating, loose bowels, blood in stool, no appetite
2022-10-22 Stopped Low appetite, recovered throughout day
2022-10-23 Stopped None