The dried whole herb portion of dog’s tail grass can be infused into water for drinking. The dried whole herb is usually used as medicine, which has the effects of clearing the liver and improving eyesight (removing liver fire to promote vision restoration), relieving heat and dispelling dampness, and can be used in the treatment of heat-induced redness and swelling of the eyes and pain, jaundice due to dampness-heat, carbuncle, swelling and ringworm, and pediatric chancre (a kind of chronic disease of children, which is characterized by emaciation of the body, dietary abnormality, abdominal distension, and sparse and withered hair), etc. The adverse effects and contraindications of this medicine are not known. The adverse reactions and contraindications of the drug are not clear, but it should be noted that it should not be used by patients with spleen and stomach deficiency (spleen and stomach weakness and cold). However, the efficacy of taking it in water is limited and it cannot replace the medication to treat the disease. If you need to use Dogwood, it is recommended to go to a regular hospital, under the guidance of a professional physician to identify and treat.