There is no such thing as the best herbal medicine to tonify yin. Herbal medicines that can be used to tonify yin include Bei Sha Shen, Mai Dong, Lily of the Valley, Zuo Gui Wan, and Mai Wei Di Huang Wan. Please do not use the medicines by yourself to avoid adverse reactions. 1. Beisha ginseng, with the effects of nourishing yin and clearing the lungs (getting rid of lung-heat by nourishing the fluid in the lungs), benefiting the stomach and generating fluids (nourishing the stomach by replenishing the fluid in the stomach), can be used for coughing with lung-heat and dryness, gastric yin insufficiency (insufficient yin fluid in the stomach), and injury of fluids in febrile illnesses. It is not suitable to be used together with veratrum. 2. Ophiopogon, has the effect of nourishing yin, moistening the lung and clearing the heart, can be used for yin deficiency consumptive cough, paralysis of the throat (pharyngeal redness, swelling and pain, or dryness, foreign body sensation, or pharyngeal itching, discomfort, dysphagia), sore throat, internal heat and thirst (internal fever accompanied by more food, more drink, more urination, and other symptoms), and so on. 3. Lily, with the effect of nourishing yin and moistening the lungs (nourishing the lungs by replenishing the lung fluid), clearing the heart and calming the mind (stabilizing the mind by removing internal heat), can be used for yin deficiency and dry cough, deficiency and vexation (vexation caused by deficiency heat in the body) palpitations, insomnia and dreaming. It is not recommended for people with wind-cold cough and loose stools (thin and unformed feces). 4. Zuo Gui Wan is composed of Radix Rehmanniae Praeparata, Semen Cuscutae, Radix Achyranthis Bidentatae and so on. It has the effect of nourishing the kidney and tonifying yin. It is used for the deficiency of genuine yin, lumbago and knee weakness, night sweating (abnormal sweating after going to sleep and stopping sweating after waking up), spermatorrhea, and fatigue (lack of spirit) and dryness of mouth, etc. It is not recommended for patients with cold and flu. It is not suitable for patients with cold and flu. Pregnant women should not take it, and children are forbidden to take it. 5. Mai Wei Di Huang Wan is composed of Radix Rehmanniae Praeparata and Cornu Cervi Pantotrichum. It has the effect of nourishing the kidney and nourishing the lung. It is used for lung and kidney yin deficiency, dizziness and tinnitus, lumbar and knee pain and weakness. If you need to take the above drugs, it is recommended to follow the doctor’s instructions.