Side effects are not excluded. Under mistletoe therapy, however, rarely any significant adverse effects have been observed under intended use. If the dosage is too high, so-called excessive local reactions with a diameter of more than 5 cm may occur. In this case, treatment should only be continued after symptoms have subsided and in a reduced dose (next lower dose). The same applies to strong general reactions such as an increase in body temperature to over 38°C. A medical examination by the doctor is recommended.