There is no such thing as how many times a week is the best time to drink yellow essence in water, it can be used as needed under the guidance of a doctor. Huangjing is the rhizome of Huangjing, Multiflora Huangjing and Dianhuangjing from the genus Huangjing of the lily family. It is sweet in nature, flat in taste, and belongs to the spleen, lung and kidney meridians. It has the functions of nourishing yin and moistening the lungs (nourishing the lungs by replenishing the lung fluid), tonifying the spleen and the qi, and nourishing the kidney essence. Huang Jing is used for coughing due to yin deficiency and lung dryness, which is characterized by dry cough with little or no phlegm, or even hemoptysis, accompanied by dry mouth, etc. It can also be used for spleen deficiency, which is characterized by fatigue, loss of appetite, etc. It can also be used for kidney essence deficiency, which is characterized by lumbar and knee soreness, impotence, spermatorrhea, ringing in the ears, dizziness and uncertainty of the eyes, premature whitening of the beard, and physical weakness, etc. It is usually taken in a decoction as a supplement to the spleen and the lungs. Huang Jing is usually decocted and taken internally, but if used to brew water for drinking, its effect may be slowed down, depending on individual circumstances. Note that it is contraindicated in cases of deficiency and coldness of the spleen and stomach (weak and cold spleen and stomach), diarrhea, phlegm-dampness congestion, and platitude (stomach fullness and discomfort) and stagnation of qi. Yellow essence should not be used in large quantities for a long period of time to avoid too much tonic and internal heat, it is recommended to ask your doctor to clarify the exact dosage and frequency of use.