The aim of this study is to investigate the effects of the Ankaferd Blood Stopper (R) (ABS), on cell viability, cytotoxicity, and erythrocyte numbers in in vitro cultured human blood cells. We studied the cytotoxic effects of the ABS using lactate dehydrogenase (LDH) assay, cell proliferation (WST-1) assay and hemolytic assay. The cytotoxicity increased when cells were treated with ABS dilutions of 5%, 12.5%, 25%, and 50% (p < 0.05). Moreover, treatment of the cells with the same concentrations significantly elevated the cell number at 24 and 48 h (p < 0.05). ABS causes a significant increase (p < 0.05) in the hemolytic activity on human erythrocytes and hemolytic activity increases with increase in ABS concentrations. The red blood cell aggregation and cell membrane disruption during the coagulation process lead to induction of hemolytic activity and increase of LDH level in cell culture medium. In addition, ABS has proliferative effects on human leukocytes. Based on these results, ABS can be used as an alternative blood stopping agent safely.