USA Store·#1 Nattokinase in the USA
Cardiovascular Science · Radical Transparency

The only cardiovascular brand that 3rd-party tests every batch.

We tested 7 of America's top-selling Nattokinase brands. Every single one was underdosed — one had just 17.8% of what was on the label. So we built the one we'd take ourselves: manufactured in our own facility, independently lab-verified every batch, every certificate published online.

Excellent★★★★★Trustpilot · 285 reviews
Happy Steporbit customer
100%
Of batches independently tested
5,000FU
Lab-verified per capsule
100K+
Bottles shipped to Americans
0
Batches sold untested
Every single batch · Zero exceptions

We test every batch, then publish the results.

The supplement industry's dirty secret is that most brands never test what they sell. We do the opposite. Every batch we manufacture is sent to SORA Labs, an ISO 17025:2017 accredited third-party laboratory, before it ever reaches your door. Every Certificate of Analysis is published online — scannable, searchable, and free to view.

01

Raw ingredients tested on arrival

Every raw ingredient is tested for heavy metals, microbials, and potency before it enters our Oxford facility. If it fails, it never goes into production.

02

Manufactured in-house under GMP

We don't outsource to contract manufacturers. Every capsule is made in our own GMP-certified UK facility in Kidlington, Oxford — fully traceable, batch by batch.

03

Finished batch tested independently

A sample from every finished batch goes to SORA Labs for third-party verification. Potency, purity, heavy metals, microbial contamination — all tested by an accredited lab with zero ties to us.

04

Certificate published before shipping

Every Certificate of Analysis is uploaded to our public testing database. Scan the batch code on your bottle and read the exact lab report for the capsules in your hand.

SORA Labs
Independent Testing

ISO 17025:2017
ACCREDITED

Certificate of Analysis
Nattokinase Arterial Support
Batch
#2026-04-072
Test Date
14 Apr 2026
Assay
Fibrinolytic FU
Label Claim
5,000 FU
Lab Result
5,201 FU104.0% of label claim
PASS
VERIFIED
Tested by SORA Labs
The Investigation

We tested 7 of America's top brands. All 7 were ripping people off.

We bought the best-selling Nattokinase pills on Amazon and sent them to SORA Labs (ISO 17025:2017) — the same accredited laboratory we use for our own batches. Same enzyme assay. Same lab. Same day.

BrandLabel ClaimLab Result% of ClaimVerdict
Steporbit ★5,000 FU / capsule>6,720 FU / capsule134%Pass
Horbaach4,000 FU / 2 caps3,720 FU / 2 caps93%Marginal
Double Wood4,000 FU / 2 caps2,800 FU / 2 caps70%Fail
Luma Nutrition4,000 FU / 2 caps<2,660 FU / 2 caps<66.5%Fail
Bulk Supplements4,000 FU / capsule<2,680 FU / capsule<67%FAIL
Hybrid Health5,000 FU / 2 caps1,380 FU / 2 caps27.6%FAIL
Raibu2,000 FU / capsule528 FU / capsule26.4%FAIL
Vinco4,000 FU / 2 caps711 FU / 2 caps17.8%FAIL

All testing performed by SORA Labs (ISO 17025:2017). 7 out of 7 competitor brands delivered less than what they promised on the label. One brand had just 17.8% of label claim — meaning if you paid $30, you got $5 worth of actual product. The rest? Filler.

Watch our full investigation. We show you the labels, the lab reports, and the math.

A Doctor's Take

Every American over 40 should know about this.

Watch Dr. Karen Vieira, PhD explain why Nattokinase matters so much for Americans right now — and why most heart-health pills on the shelf today are letting people down.

Dr. Karen Vieira, PhD — Biomedical Sciences researcher and published author on enzyme therapeutics.

Steporbit Nattokinase
The Formula

Nattokinase Arterial Support

5,000 FU of pure, lab-verified nattokinase enzyme — the exact dose used in the clinical studies that proved it works on arterial plaque.

  • 5,000 FU of clinically-studied nattokinase per capsule
  • SORA Labs verified — >134% of label claim
  • Manufactured in our own GMP facility
  • Fermented from non-GMO soybeans
  • Vegan, gluten-free, no fillers or binders
  • One capsule a day · 30 servings per bottle
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Common Questions

Things people ask us.

Three things that almost nobody else does — and certainly not all three together.

One: we manufacture in our own GMP-certified facility. We don't subcontract to a third-party blender, which means we control what goes in the capsule, the dose, and the quality of the raw material. Two: every single batch is tested by an independent ISO 17025-accredited laboratory before it ships. Not once a year. Not on samples we cherry-picked. Every batch. Three: we publish every certificate of analysis online, searchable by the batch number printed on your bottle. If you can't verify it, we don't sell it.

Supplements you can actually verify. Finally.

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