Serrapeptase is a big molecule and there is a real question as to whether it is actually absorbed intact. I use it in my toothpaste formula because it breaks up bacterial biofilms.
Nattokinase has a molecular weight of about 500. Serrapeptase weighs in at about 100 times that - a vastly larger molecule. So they are not comparable.
Edit - Preceding retracted due to being in error
Edit2 - Confirmed that the variety of nattokinase used in the above study is the high molecular weight variety.
"Gastrointestinal absorption of macromolecules, such as, proteins can be explained by three mechanisms as follows [16,17].
First, proteins are absorbed via receptor mediated endocytosis are as
some growth factors. Second, proteins are absorbed by pinocytic
vesicles, which are formed by the brush border membrane of the
intestine, and normally fuse with lysosomes to form phagolysomes. Only
if a protein escapes hydrolysis can it conceivably enter the
extracellular space and reach the blood stream. Third, protein
absorption by trans-epithelial transport via the M cells of Peyer's
patches could be involved. Foreign proteins, such as, lumbrokinase are
unlikely to be absorbed via receptor-mediated endocytosis, and thus, the
intestinal absorption of lumbrokinase is more likely to involve the
second and third mechanisms. Because it is a complex of strong serine
proteases, lumbrokinase is resistant to degradation by some cellular
enzymes, and thus, it could be transferred intact and across the cell
membrane by pinocytic vesicles or epithelial cells (M cells)."
~
It is not clear to me how much size matters if either of the latter two transport mechanisms are involved; Fig 2 from the article shows absorption across the 33.6 - 54.7 kDa range.
Yes, there is the potential for blood thinning, so you would definitely never want to take it with any other type of blood thinner, even the natural ones like fish oil, vitamine and aspirin to name just three and given the health conditions it is used for, definitely under your doctors approval and supervision.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.