nattokinase

Nattokinase is an enzyme produced when the bacterium Bacillus subtilis ferments soybeans to make natto, a traditional Japanese food. It is sold as a capsule or tablet dietary supplement. Like other dietary supplements, nattokinase products are not reviewed by the U.S. FDA for safety or effectiveness before they reach the market, and the manufacturing rules that apply to them are less strict than those for prescription or over-the-counter drugs.

We could not find an authoritative NIH Office of Dietary Supplements, NCCIH, or MedlinePlus fact sheet that reviews the evidence for nattokinase specifically. Independent, rigorous evidence for the uses listed above is therefore limited, and those uses reflect how the product is marketed rather than proven benefits. More broadly, NCCIH points out that the scientific backing for claims made about dietary supplements is frequently weak or absent, and that a product bought in a store or online can differ in important ways from the version studied in research. Anyone considering nattokinase should treat marketing claims with caution and should not rely on it to prevent or treat any disease.

There is no established or government-recommended dose for nattokinase, and the amounts in commercial products vary widely. Because supplements are not standardized or verified for content the way drugs are, talk to a doctor or pharmacist before starting nattokinase, especially if you take other medicines or have a health condition.

Nattokinase has not been thoroughly evaluated for safety by U.S. government health authorities. NCCIH cautions that certain dietary supplements may raise the risk of bleeding or affect how you respond to anesthesia, so anyone planning surgery or a dental procedure should tell their health care providers about every supplement they take, as far in advance as possible. Like most supplements, nattokinase has not been adequately tested in people who are pregnant or breastfeeding or in children, so these groups should avoid it unless a clinician advises otherwise.

Because no authoritative NIH ODS, NCCIH, or MedlinePlus review of nattokinase was found, its full side-effect profile is not well characterized. If you experience any side effects, report them to your health care provider and, where appropriate, to the product's manufacturer.

Dietary supplements can interact with medications, and NCCIH specifically warns that some may increase the risk of bleeding. As a precaution, people who take blood thinners or antiplatelet drugs (such as warfarin, aspirin, or other anticoagulants), or who have a bleeding disorder, should be especially careful and should talk to a clinician before using nattokinase. Always tell your doctor and pharmacist about every supplement you take so they can check for possible interactions.