Herbal and nutritional supplements are ubiquitous in modern medicine alongside prescribed medicines. While evidence surrounding efficacy and safety are often lacking, some have the potential for further study. One of these is nattokinase, the active ingredient of natto, a Japanese soybean food made through fermentation with Bacillus subtilis. Despite its name, nattokinase (NK) is a protease rather than a kinase, with multiple pharmacological events that have the potential to act as a significant reductor of cardiovascular risk factors. One of the first documented pharmacological effects of NK was its potent thrombolytic effects; at the same concentration, it has been found to be four times more potent than plasmin at thrombus dissolution. In addition, it also promotes the release of tissue plasminogen activator (tPA) to increase endogenous plasmin, without a significant effect in bleeding. With these effects, NK has the potential to be used as an thrombolytic agent in acute thrombotic pathologies, with a more favourable side effect profile. NK has also been found to reduce intimal thickening with regular dietary intake, proposed to be due to antioxidant effects reducing LDL peroxidation and improving lipid metabolism. This effect extends also to systemic lipid levels, with a significant reduction in LDL, triglycerides and total cholesterol. Finally, an inhibitory effect on thromboxane B2 formation from activated platelets was also found, similar to the antiplatelet mechanism of aspirin. In combination, this presents significant potential for primary prevention in atherosclerotic disease progression. While novel drugs with supposedly endless benefits should always be received with caution, NK does indeed appear to have some evidence backing its claims. While large-scale human trials are still needed to validate its benefits, results so far are promising.