Complementary and alternative medicine (CAM) treatments are therapies that aren’t part of standard medical care. For people with amyloidosis — a rare disease that happens when a buildup of abnormal proteins damages organs — CAM might include dietary changes, vitamins, or supplements.

Because amyloidosis can affect many parts of the body, it’s important to speak with your amyloidosis specialist before trying any new therapy, including natural or over-the-counter options.

One supplement that some MyAmyloidosisTeam members have discussed is nattokinase. “I heard that nattokinase destroys amyloidosis. Is anyone taking it?” one member asked. Another said, “I think nattokinase is reducing amyloids in my bladder.”

As of April 2025, no clinical studies in people show whether nattokinase is safe or effective for treating amyloidosis. Some early laboratory research suggests nattokinase might help with certain symptoms, but more studies are needed.

This article explores what the research says about nattokinase, how this supplement might help people with amyloidosis, and what risks you should know about.

What Is Nattokinase?

Nattokinase is an enzyme — a type of protein that helps chemical reactions happen in the body. This enzyme is found naturally in natto, a traditional Japanese food made by fermenting soybeans with a type of bacteria called Bacillus subtilis (B. subtilis). During fermentation, B. subtilis produces nattokinase. In Japan, natto is often eaten with rice for breakfast or used to season meat and vegetables.

In the 1980s, researchers isolated nattokinase from natto while looking for food substances with thrombolytic activity (the ability to break down blood clots). Nattokinase became available as a dietary supplement in the late 1990s.

Note that nattokinase isn’t approved by any national health agencies to treat health conditions. The U.S. Food and Drug Administration (FDA) doesn’t approve supplements for safety and effectiveness before they’re marketed, nor does it regulate them as vigorously as it does medications.

What Claims Have Been Made About Nattokinase?

Nattokinase is promoted as a natural remedy for several health conditions. For example, marketers claim that nattokinase can:

• Help prevent blood clots
• Lower hypertension (high blood pressure)
• Treat Alzheimer’s disease
• Treat cancer

However, these claims are not backed by strong scientific evidence. So far, only a few studies have tested nattokinase in people. Most findings come from studies that are in vivo (in animals) or in vitro (using tissue samples in a laboratory).

Some early research in people suggests that nattokinase may hold promise for reducing blood pressure and the risk of deep vein thrombosis (DVT) — a blood clot that forms in a deep vein, usually in the legs. However, the claims for nattokinase for Alzheimer’s disease and cancer are based only on laboratory studies, not on testing in people.

How Might Nattokinase Help Amyloidosis?

No studies have directly tested nattokinase for amyloidosis, but research from Alzheimer’s studies offers clues about how it might work. Both conditions involve amyloid fibrils, which are clumps of harmful proteins that stick together in the body and can build up in organs, leading to damage.

In a 2009 laboratory study, researchers explored the amyloid-degrading ability of nattokinase. Later lab studies confirmed that nattokinase can slowly break apart amyloid plaques under conditions similar to those of the human body.

A 2023 study in mice showed that nattokinase may improve Alzheimer’s symptoms by reducing inflammation — the body’s response to injury or infection. Because some types of amyloidosis are linked to chronic inflammation, this action might be helpful. However, more research is needed to see if nattokinase has the same effect in people with amyloidosis and, if so, what types of the condition.

Another study, done in 2013 with rats, suggested that nattokinase might help reduce some features of Alzheimer’s disease. The researchers found that nattokinase increased the activity of a gene called ADAM10. This gene produces a protein that, in other studies, was shown to help break down amyloid precursor protein (APP), which can form amyloid plaques in Alzheimer’s.

The study didn’t directly test whether nattokinase breaks down APP itself. In theory, boosting ADAM10 activity may help reduce amyloid buildup in the brain, but this hasn’t been tested in people or in amyloidosis, which involves different types of amyloid-forming proteins. It’s important to remember that results seen in Alzheimer’s research may not apply to amyloidosis.

What Are the Risks of Taking Nattokinase?

It’s easy to assume that supplements made from a natural source aren’t dangerous, but that’s not always true. Like many supplements, nattokinase may cause serious side effects or interact with other medications. Even if nattokinase turns out to be helpful, doctors don’t know the safest or most effective dose to recommend because there’s not enough research to guide them.

Nattokinase Side Effects

Because of the lack of clinical studies, researchers don’t know all the possible side effects of nattokinase. In a small 2015 study in the International Journal of General Medicine, 17 females took nattokinase for four weeks with no reported side effects. However, some case reports (individual accounts) linked this supplement to serious health problems.

The biggest concern is the risk of dangerous bleeding or a stroke if an existing blood clot breaks loose. One person taking nattokinase for its blood-thinning effects developed shortness of breath, chest pain, and blood clots.

In another report, a person who took nattokinase for atrial fibrillation (irregular heart rhythm) died of internal bleeding.

In addition, an individual who injected nattokinase had to have their arm amputated due to severe tissue damage. Some people also had serious allergic reactions to nattokinase, including hives and anaphylaxis.

Nattokinase Drug Interactions

Nattokinase may increase the risk of bleeding when taken with blood thinners, including:

• Aspirin
• Warfarin (Coumadin)
• Anticoagulants such as apixaban (Eliquis), enoxaparin (Lovenox), and heparin
• Antiplatelet medications such as clopidogrel (Plavix), prasugrel (Effient), and ticagrelor (Brilinta)

Nattokinase may also interact with other drugs in ways researchers don’t yet know about. To avoid serious side effects or interactions, tell your healthcare provider about every medication and supplement you take, including over-the-counter products.

Check With Your Healthcare Team

Before trying any new type of CAM or supplement, like nattokinase, it’s important to talk with your healthcare provider. Complementary and alternative therapies should never be used alone or instead of prescribed treatments for amyloidosis.

Even though nattokinase comes from food, the supplement form may not be safe for everyone. You should avoid taking nattokinase if you:

• Are allergic to soybeans or natto
• Have a blood-clotting disorder
• Take blood thinners
• Have a history of stroke or stomach ulcers
• Are pregnant or breastfeeding

Your doctor can help you make sure your amyloidosis treatment plan is the safest and most effective for your needs. They may recommend other CAM therapies or suggest healthy lifestyle changes, such as cutting back on salt, to help manage your symptoms and protect your organs.

Talk With Others Who Understand

MyAmyloidosisTeam is the social network for people with amyloidosis and their loved ones. On MyAmyloidosisTeam, members come together to ask questions, give advice, and share their stories with others who understand life with amyloidosis.

Have you talked to your doctor about nattokinase for amyloidosis? Do you use other complementary and alternative therapies as part of your amyloidosis plan? Share your experience in the comments below, or start a conversation by posting on your Activities page.