Nattokinase

Nattokinase is an enzyme extracted from Natto, a traditional Japanese food made by fermenting soybeans. It's commonly sold as a dietary supplement and is most often marketed for heart and circulatory health.

What it's claimed to do

Research has explored nattokinase for:

• Supporting healthy blood flow
• Breaking down fibrin (a protein involved in blood clot formation)
• Mildly lowering blood pressure in some people
• Supporting cardiovascular health

What the evidence says

The evidence is promising but not definitive.

Some small clinical studies have found:

• Blood pressure: A modest reduction (around 3–5 mmHg in some people with mildly elevated blood pressure).
• Blood clotting: It appears to have fibrinolytic (clot-dissolving) activity in laboratory and some human studies, but it should not be considered a substitute for prescription blood thinners.
• Cholesterol: May help lower bad cholesterol