Drug & supplement interaction

Nattokinase + Aspirin, Meprobamate

Aspirin, Meprobamate brand name: Micrainin.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Nattokinase has a moderate interaction with Aspirin, Meprobamate. Nattokinase might increase the risk of bleeding when used with anticoagulant/antiplatelet drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Nattokinase and Aspirin, Meprobamate

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Aspirin, Meprobamate

Aspirin, Meprobamate falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Nattokinase interacts with.

Nattokinase might increase the risk of bleeding when used with anticoagulant/antiplatelet drugs.
Nattokinase has thrombolytic and anticoagulant effects. There is a case report of intracranial hemorrhage in a patient who added nattokinase to aspirin therapy.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

The product you're asking about (brand name Micrainin) combines two things: aspirin, which thins the blood by blocking platelets from sticking together, and meprobamate, a sedative for tension. The piece that matters here is the aspirin. Nattokinase also nudges your blood toward thinner and more clot-dissolving, so stacking the two means both are pushing in the same direction at once. That can raise your bleeding risk, things like easy bruising, nosebleeds, bleeding gums, or a stomach bleed.

To be honest, the evidence is thin. It rests mostly on lab data plus one case report of bleeding in the brain in someone combining nattokinase with aspirin. That's rare, but serious enough to respect. Please check with your pharmacist or doctor before adding nattokinase, and don't change your medicine on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Suzuki Y, Kondo K, Matsumoto Y, et al. Dietary supplementation of fermented soybean, natto, suppresses intimal thickening and modulates the lysis of mural thrombi after endothelial injury in rat femoral artery. Life Sci 2003;73:1289-98.. PubMed
  2. Sumi H, Hamada H, Nakanishi K, Hiratani H. Enchancement of fibrinolytic activity in plasma by oral administration of nattokinase. Acta Haematol 1990;84:139-43.
  3. Chang, Y. Y., Liu, J. S., Lai, S. L., Wu, H. S., and Lan, M. Y. Cerebellar hemorrhage provoked by combined use of nattokinase and aspirin in a patient with cerebral microbleeds. Intern Med 2008;47(5):467-469. PubMed
  4. Kurosawa Y, Nirengi S, Homma T, et al. A single-dose of oral nattokinase potentiates thrombolysis and anti-coagulation profiles. Sci Rep 2015;5:11601. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Nattokinase Also Interacts With Other Medications

Nattokinase has 288 moderate known drug interactions in our database — the Aspirin, Meprobamate one above is one of them. If you take anything else, check it against the full list below.

Moderate 288 No known interaction 2,542 (incl. Aspirin, Meprobamate)
Taking anything else?

Check Another of Your Medications Against Nattokinase

Covers the 2,830 medications we’ve checked against Nattokinase. Pick one to open its full report.

From our Q&A

Questions About Nattokinase or Aspirin, Meprobamate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Nattokinase or Aspirin, Meprobamate, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Aspirin, Meprobamate

This page covers Nattokinase only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Meprobamate page lists 250 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Danshen (major) and Piracetam (major).

By severity: 7 major · 214 moderate · 29 minor.

From our pharmacist’s overview on the Aspirin, Meprobamate page

“Bleeding is the risk that towers over everything else on this page. Micrainin pairs meprobamate with aspirin, and aspirin already thins the blood, so 202 of the 250 supplements listed here can push that effect further.”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin, Meprobamate interaction page

One more smart check

Taking Nattokinase as Part of a Dietary Supplement Product? Check It for Interactions

We hold 509 real supplement products containing Nattokinase, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Nattokinase. Your product may carry other ingredients that interact with Aspirin, Meprobamate too, on top of Nattokinase — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Nattokinase and Aspirin, Meprobamate Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Nattokinase
Top 25%

#243 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Aspirin, Meprobamate
Steady interest

#1,567 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Nattokinase

What is Nattokinase?

Nattokinase
  • Heart and circulatory health
  • Blood clot prevention
  • High blood pressure
  • Improving blood flow
  • Cholesterol support

Nattokinase is an enzyme from the fermented soybean food natto that may have mild blood-thinning and blood-flow effects. Some small studies hint at benefits for blood pressure and circulation, but the evidence is limited and more research is needed. Because it can affect clotting, talk to your pharmacist or doctor before trying it, especially if you take medicines or have a bleeding risk.

Read the full Nattokinase monograph & all interactions
Keep checking

Other Drugs & Nattokinase

Browse every other medication we’ve checked against Nattokinase — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
288Moderate
0Minor
2,541No known interaction
288 Moderate 2,541 No interaction
Moderate

288 interactions

Showing 60 of 288 moderate interactions — see all 288 on the Nattokinase page.

No interaction 2,541 drugs checked — show the list

We also checked Nattokinase against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,541 medications checked with no known interaction — see the full Nattokinase list.

See the full Nattokinase interactions page
See every supplement checked against Aspirin, Meprobamate, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Nattokinase monograph › Uses, safety, and every drug interaction in one place Aspirin, Meprobamate supplement interactions › Every supplement checked against Aspirin, Meprobamate, ranked by severity Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Nattokinase and Aspirin, Meprobamate Together: Common Questions

Can you take Nattokinase with Aspirin, Meprobamate?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Nattokinase and Aspirin, Meprobamate interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Aspirin, Meprobamate and Nattokinase?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.