Nattokinase vs Serrapeptase: What Separates Them

A woman in a shop aisle reading the back of a plain supplement bottle

These 2 enzymes get sold side by side and are often assumed to be interchangeable, which they are not. They come from 2 different organisms and act on different targets.

One of them has 10 clinical trials behind it. The other does not.

Quick Answer: Nattokinase or Serrapeptase?

They are different enzymes with different origins. Nattokinase comes from Bacillus subtilis fermenting soybeans and acts on fibrin, the protein in clots. Serrapeptase comes from bacteria in the silkworm gut and is sold mainly for inflammation and mucus. Nattokinase has 10 clinical trials and 2 meta-analyses on PubMed; serrapeptase has far less for the claims made about it.

Key Takeaways

  • The 2 enzymes come from entirely different organisms and act differently.
  • Nattokinase targets fibrin, while the other 1 is sold for inflammation.
  • PubMed holds 10 nattokinase clinical trials and 2 pooled meta-analyses of them.
  • 1 published case describes a patient injecting an oral combination product.
  • We stock nattokinase at 2000 FU and exactly 0 serrapeptase products.

Different Organisms Entirely

The pairing on shop shelves suggests a family relationship that does not exist.

Nattokinase Serrapeptase
Source organism Bacillus subtilis, in fermented soy Serratia, from the silkworm gut
Main target Fibrin, the protein in clots Inflammatory proteins and mucus
Sold mainly for Circulation and clotting markers Inflammation, sinuses, scar tissue
Measured in Fibrin units, FU Serratiopeptidase units, SPU
Clinical trials on PubMed 10 Fewer, for the claims made

What the first of the 2 actually does is in the nattokinase primer.

What Each Is Claimed to Do

The claims overlap in marketing far more than the mechanisms overlap in biology.

  • Nattokinase claims: Circulation, blood pressure, clotting markers.
  • Serrapeptase claims: Inflammation, sinus congestion, scar tissue.
  • Shared marketing term: Systemic enzyme, which is not a scientific category.
  • Shared caution: Both are described as affecting bleeding.

Systemic enzyme is a shop category rather than a pharmacological one, and treating 2 unrelated proteins as one class is where most of the confusion starts.

Two identical dishes side by side holding two different kinds of capsule

The Evidence, Compared Honestly

This is the part worth being precise about, because it is the only real basis for choosing.

  • Nattokinase records: 331 on PubMed, 102 tagged human.
  • Nattokinase trials: 10, with 2 meta-analyses.
  • Largest nattokinase trial: 265 adults, median age 65.3.
  • Serrapeptase: A thinner file for the claims routinely made.

The largest nattokinase trial ran in 265 people and explicitly noted that no large-scale long-term cardiovascular study had been conducted before it.[1]Nattokinase atherothrombotic prevention study: A randomized controlled trial — Clinical Hemorheology and Microcirculation (2021) View source A 2024 meta-analysis pooled the randomized evidence.[2]Nattokinase Supplementation and Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials — Reviews in Cardiovascular Medicine (2024) View source

The Case That Explains the Warning Labels

There is 1 published case involving a product containing both enzymes, and it is worth knowing even though it does not describe normal use.

  • The product: An oral supplement combining serrapeptase and nattokinase.
  • What the patient did: Injected it into a blood vessel.
  • Why: Self-treatment researched online for Peyronie's disease.
  • Outcome: Vascular necrosis of the upper extremity.

The case is not about swallowing either enzyme.[3]Vascular Necrosis of the Upper Extremity After Self-Treatment for Peyronie's Disease — Sexual Medicine (2021) View source It is included because it is the clearest illustration of why these are oral products and nothing else. The oral risks are set out in what the safety record shows.

Hands beside two stacks of defocused papers, one clearly taller than the other

Combination Products

Many products carry both, and the reasoning is worth examining before you buy one.

  • The pitch: Broader enzyme coverage from 2 actives.
  • The problem: 0 trials of the combination for any endpoint.
  • The other problem: Both are said to affect bleeding, so risks add.
  • What you lose: The ability to know which one did anything.

The same objection applies to any multi-ingredient supplement, and it applies with more force when both ingredients push on clotting.

Where the food version of all this fits is in eating natto instead.

What We Stock, and Why

Being direct about this, since the page compares a product we sell with one we do not.

  • Nattokinase: Yes, at 2000 FU per capsule.
  • Serrapeptase: 0 products.
  • Why: The trial base for the enzyme we sell is the larger of the 2.
  • What we will not do: Recommend a category we have not stocked.

If the enzyme with the bigger file is what you want, a single 2000 FU serving is what our label carries.

Do Not Start Either Enzyme, and Speak to a Clinician First, If

  • You take warfarin, a DOAC, aspirin, clopidogrel or any other anticoagulant or antiplatelet
  • You have a mechanical heart valve, a stent or any implanted cardiac device
  • You have a bleeding disorder such as haemophilia, or a history of haemorrhagic stroke
  • You have surgery or a dental procedure booked within the next 2 weeks
  • You are pregnant, breastfeeding, or allergic to soy or natto
A man sitting at his kitchen table with one plain supplement bottle and a glass of water

Frequently Asked Questions

What is the difference between nattokinase and serrapeptase? +

They come from 2 different organisms and act on different proteins. Nattokinase targets fibrin, serrapeptase is sold for inflammation.

Which is better, nattokinase or serrapeptase? +

For anything clotting-related, nattokinase has the larger file: 10 clinical trials and 2 meta-analyses on PubMed.

Can I take nattokinase and serrapeptase together? +

There are 0 trials of the combination, and both are described as affecting bleeding. Ask before stacking the 2.

Does serrapeptase thin the blood? +

It is commonly described that way, which is 1 reason combining it with nattokinase compounds the caution.

Is serrapeptase safer than nattokinase? +

Neither has been shown to be. The 7 nattokinase case reports are at least documented, which is more than can be said for many supplements.

Do you sell serrapeptase? +

No, we stock 0 serrapeptase products. We sell nattokinase at 2000 FU per capsule.

What are systemic enzymes? +

A shop category rather than a scientific one. It groups at least 2 unrelated proteins under a single marketing term.

Can these enzymes be injected? +

Absolutely not. 1 published case describes vascular necrosis of an arm after someone injected an oral combination product.

Which enzyme is better for sinuses? +

Serrapeptase is the 1 usually marketed for that, and nattokinase has 0 trials for sinus outcomes.

Related Reading