This study is being conducted because there has not been any proper studies to provide evidence that these commonly used "blood activating" herbal preparations can in fact affect blood clotting by interfering with platelet function or clotting mechanism and potentiate the antiplatelet activity of Aspirin. These are assumptions based on TCM theory, laboratory experiments and animal studies but have led to the general statement in medical literature that these herbs increases bleeding risk in patients taking Aspirin or any other anti-platelet drugs. This has resulted in advice that these herbal products should not be taken by patients on Aspirin, which is a common drug taken by many patients. We hope to prove or disprove this theoretical concern by measurement of platelet and clotting function in healthy volunteers before and after taking the herbal product, alone and in combination with Aspirin. This will help to answer the question of whether it is safe for patients to take these common "blood -activating " herbs alone or together with Aspirin.