Cardioprotectors are medicinal substances that enhance the activity and operation of the heart under both normal and pathological circumstances while thwarting the effects of various corrosive agents. In this scientific work, the cardioprotective activity of hawthorn extract is evaluated on the example of laboratory rats with artificially induced doxorubicin cardiomyopathy. Corvitin was chosen as the main substance with which the main indicators are compared. In the event of using hawthorn extract, the control of body weight and organs of the tested animals revealed minimal body weight loss as well as the closest approximation of the mass of individual organs to the normal state. The conducted ECG study showed that by many indicators, the use of hawthorn extract gave a more positive result than the use of Corvitin. A similar situation is also observed when evaluating the enzymatic parameters of blood serum and the lipid peroxidation system, and the antioxidant system. Thus, it was demonstrated through experimentation that the hawthorn extract under study prevents the development of doxorubicin myocardial intoxication in white rats and has a noticeable normalising effect on the heart muscle's functional state, not inferior in effect to Corvitin, and in some indicators, even exceeding it.