Four Substances Soup has the effect of tonifying blood and regulating menstruation, and can be used to treat hair loss caused by blood deficiency. Four Substances Soup is a class of tonic formula. It is composed of Radix Rehmanniae Praeparata, Radix Paeoniae Alba, Radix Angelicae Sinensis and Rhizoma Ligustici Chuanxiong, which have the efficacy of tonifying Blood and regulating menstruation. It can be used clinically for treating abdominal pain caused by deficiency of the Chong Ren vein and the Ren vein (deficiency of yang qi which is unable to warm the Chong Ren vein and the Ren vein), disintegration of menstrual flow, post-partum malignant discharge, and irregular menstruation. For patients with Blood stasis, Salvia miltiorrhiza may be added; for patients with Blood cold, Cannon Ginger may be added. Hair loss may be caused by Kidney deficiency, Blood heat, Blood deficiency, etc. Clinically, Si Wu Tang can be used to treat hair loss caused by Blood deficiency, but it has no therapeutic effect on other syndromes. The adverse reactions and contraindications of Si Wu Tang are not clear. Patients who need to use the drug, should be under the guidance of a doctor, not unauthorized use of drugs.