Chemotherapy drugs are commonly used in cancer treatment, despite their numerous negative side effects. Today, there are studies to reduce the side effects of these drugs and to increase their benefits by combining them with natural substances. Our study investigated the antioxidant and antiradical activities of Ellagic acid (EA), a natural substance, DOC and MIX, commonly used chemotherapeutics, as well as their combinations (EA+DOC, EA+MIX). For this purpose, the methods of DPPH• and ABTS•+ scavenging activity, Fe3+-Fe2+ and Cu2+-Cu1+ reduction capacity were used. After the study, the interactions were analysed with the combination index using Compusyn software. Concentrations with maximum synergy in combinations have been identified. For this purpose, firstly, the combination concentrations used in the antioxidant activity methods and the absorbance values were entered into the Compusyn programme. When DPPH• and ABTS•+ scavenging activity results were entered into the programme, more effective synergistic effect was observed for EA+DOC at lower concentrations (7:7µg/mL), (0.125:1µg/mL) respectively. For EA+MIX, no synergistic effect was observed with the application of DPPH scavenging activity results to the programme, while for ABTS•+ scavenging activity, more effective synergistic effect was observed at higher concentrations within the applied doses (0.750:6µg/ml). When Fe3+-Fe2+ and Cu2+-Cu1+ reduction results were applied to the programme; synergistic effect was observed at higher concentrations (17:17µg/mL) for both EA+DOC and EA+MIX and even strong synergistic effect was observed in many of them. The obtained results provide guidance for the use of these combinations in further studies, such as anticancer and enzyme studies.