Nattokinase (NSK-SD®)

Heart health & circulation

Function & benefits

An enzyme from Japanese fermented soybeans (natto) that can break down the protein fibrin; a randomised trial suggests it supports normal blood pressure and von Willebrand factor levels, and another human study that it supports normal levels of fibrinogen and clotting factors, helping blood flow freely.

Dosage & how to use

Recommended dose	2000 FU daily (about 100 mg)
Best time to take	On an empty stomach: half an hour before breakfast or an hour before bed
Frequency	Once daily

Best forms to choose

Nattokinase standardised in fibrinolytic units (FU), purified and free of vitamin K2 (such as NSK-SD®), in capsules.

Important warnings

Not for people with bleeding disorders or an active ulcer; stop two weeks before surgery or a dental procedure

Avoid it if you are allergic to soy

Not for use during pregnancy or breastfeeding

Drug interactions

Important warning: do not combine it with blood thinners or antiplatelet drugs (warfarin, heparin, aspirin, clopidogrel, newer anticoagulants) unless under medical supervision, because of the risk of bleeding. It may also strengthen blood pressure medication.

View in the supplements guide

Related supplements

Scientific references

Jensen GS et al. Integr Blood Press Control 2016 — PMID: 27785095
Hsia CH et al. Nutr Res 2009 — PMID: 19358933

📚 Published sources and research: European Food Safety Authority (EFSA) • National Institutes of Health (NIH - ODS) • PubMed / Cochrane databases

Content last updated: 17 October 2026 · Based on published sources and research (EFSA / NIH / PubMed)

⚖️ Medical disclaimer: The information and data provided here are for health education and nutritional guidance only. They are not a medical diagnosis and never replace a direct consultation with your doctor or pharmacist. Always consult your doctor before starting any supplement, especially during pregnancy or breastfeeding or when taking long-term medication.