You can eat radish when drinking Si Wu Tang.
Si Wu Tang is composed of Radix Rehmanniae Praeparata, Rhizoma Ligustici, Rhizoma Ligustici, Radix Angelicae Sinensis and Radix Paeoniae Alba, and there is no research to suggest that taking these four medicines with radish will reduce the efficacy of the medicines or produce other adverse reactions.
Four Substances Soup is a traditional Chinese medicine formula composed of Radix Rehmanniae Praeparata, Radix Angelicae Sinensis, Rhizoma Ligustici Chuanxiong and Radix Paeoniae Alba, which is effective in tonifying and regulating blood, and is used for treating the symptoms of deficiency of blood in the camp and blood stagnation, such as dizziness, palpitations, insomnia and lack of splendor of the complexion, or irregular menstruation of a woman with scanty menstruation or menstruation closure, and pain in the umbilicus and abdomen.
Radish, the Chinese medicine Lai Chi, has the efficacy of eliminating food, lowering qi, resolving phlegm and stopping bleeding, and can be used to treat dyspepsia, food stagnation (the accumulation of poorly digested food in the stomach), flatulence, acid swallowing (swallowing of acid from the stomach upward to the mouth and pharynx), constipation, coughing up blood and other illnesses. Its adverse effects are not clear, and it should not be consumed raw by people with cold spleen and stomach, and should not be used with ginseng.
There are no studies showing that taking Si Wu Tang and radish together will reduce the efficacy of the medicine or produce other adverse reactions, so they can be taken together. It should be noted that the use of traditional Chinese medicine needs to be under the guidance of a professional physician to identify the evidence, do not self-medication, so as not to affect the health of the body.