Siwu Tang is a blood tonic formula composed of Bai Shao, Shu Di, Chuanxiong and Angelicae. It can treat various kinds of blood deficiency caused by panic, insomnia, dizziness, pallor, weakness or women with low menstrual flow, delayed menstruation, abdominal pain after menstruation, and can be used as long as it meets two or more of the above symptoms and the tongue is not thick and greasy, and is usually taken in the morning, in the afternoon and in the evening. The liver is the master of blood, the kidney stores essence, and menstruation is the residual energy of the kidney essence. Therefore, Shu Di Huang is used to greatly nourish the liver and kidney, and is an important medicine for nourishing Yin and replenishing blood, and Bai Shao enters the liver to nourish liver blood, together with Shu Di. Too much tonic blood will produce stasis of blood, so Angelica sinensis is used to tonify and invigorate the blood and correct the side effects of stasis of blood. Chuanxiong is said to travel up to the head, down to the sea of blood, and around the whole body. Such an appropriate combination makes blood tonification effective.