Nattokinase benefits and dangers: is it worth the hype?

Do you have issues like high blood pressure, or an increased risk for heart disease? If you’re hesitant to start a new medication, you may be considering nattokinase supplements instead.

Nattokinase in a bowl

Nattokinase, an enzyme derived from fermented soybeans, are a popular supplement to take for health problems such as heart disease and high blood pressure. Before you try nattokinase, it’s important to consider both the benefits and risks that come with starting a new supplement.  

If you’d like to try it for yourself, check out our article about the best nattokinase supplements to choose from. 


Overall, nattokinase is meant to help improve circulatory health, but it has other benefits as well, such as improving brain and gut health. 

Cardiovascular Health

Nattokinase can break down fibrin, which is a protein involved in creating blood clots. It can both prevent blood clots and even break down clots that have already formed, which can in turn protect you from conditions like strokes, heart attacks, pulmonary embolisms, and deep vein thrombosis. It also enhances circulation throughout the body, which can reduce heart strain and improve overall health with the increase of nutrients and oxygen in the blood. 

Blood Pressure 

Studies show that nattokinase can help lower both systolic and diastolic blood pressure in those with hypertension, or high blood pressure. It can inhibit the angiotensin-converting enzyme (ACE), which promotes blood vessel dialation. It’s important to note that men saw a bigger decrease in their blood pressure levels as a result of nattokinase than women. 


Nattokinase has been shown to decrease the levels of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukins (IL-6, IL-1β). These cytokines play a key role in promoting inflammation within the body, and nattokinase can help mitigate the inflammatory response by reducing their levels. Because of the fermentation in the supplement, nattokinase can also prevent inflamation in your digestive system. 

Digestive Health

Like other fermented foods, nattokinase and its probiotics can promote a healthy balance of bacteria in the digestive microbiome and improve overall function. Improving your gut health can also help you absorb nutrients and can benefit your overall immune system. 

Brain Health

Nattokinase helps improve circulation and blood flow, which in turn helps blood travel and circulate in the brain. It also helps promote neurogenesis, which is the development of nervous system tissue, especially after strokes. 


While nattokinase is overall helpful for people struggling with heart issues, it's important to keep potential side effects in mind. As with any supplement, it's crucial to consider individual health conditions and consult with a healthcare provider before adding it to your regimen. 

Clot Relocations, Bleeding & Bruising

Since nattokinase is meant to help break down fibrin, it can cause issues such as excessive bleeding and bruising due. It can help break down blood clots, but it can also cause them to move and cause further risk to your health. Those with bleeding disorders such as hemophilia or von Willebrand disease should avoid taking nattokinase, as it can cause you further health issues. 

Digestive Issues

Like most foods and supplements with probiotics, you may experience diarreha and gas because of the sudden increase of competing bacterias in your gut. Only some people experience this with probiotics, and the issue resolves itself over a few days to a couple weeks as you continue taking the supplement. 

Interactions with Medications

If you take blood thinners already, nattokinase may interact with your medication and cause an excess in bleeding, bruising, and issues with clotting like you would with a blood disorder. It’s important to discuss what supplements you can take with your current medication regimen before adding new ones. You also shouldn’t take aspirin or ibuprofen with nattokinase, as they also reduce clotting. 


If you’re allergic to soy, avoid taking nattokinase, as you could suffer from anaphylaxis, or a severe allergic reaction with symptoms such as breathing difficulties like wheezing and shortness of breath, itchiness, rash or hives, vomiting, diarrhea, low blood pressure, and unconciousness. Once you have breathing difficulties, you should immediately go to the emergency room. Most allergic reactions occur within 5 minutes to an hour after exposure. 

No matter what you’d like to take nattokinase for, it’s important to discuss the possibilities with your healthcare providers before you start.

Allison Radziwon

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