Forsythia has the effect of subduing swelling and dispersing knots, clearing heat and removing toxins, and dispersing wind-heat, so it can be applied externally to treat pustular sores caused by heat and toxins. Forsythia is used as medicine with dried fruit, bitter flavor, slightly cold, has the effect of subduing swelling and dissipating lumps, clearing away heat and detoxification, and evacuating wind-heat. It can be used to treat wind-heat colds, scrofula (mainly refers to cervical lymph node tuberculosis), high fever and thirst, dizziness, carbuncle (a kind of poisonous sores, acute suppurative diseases occurring on the surface of the body, limbs, internal organs), dengtoxin (an acute infectious disease, the skin can be seen to redden like a paint) and many other diseases. The adverse effects of forsythia are not clear, and it is not recommended for those with weak spleen and stomach, those with fever due to Qi deficiency, and those with ulcerated canker sores and diluted pus with pale color. Forsythia is usually taken by decoction and can also be used externally. Forsythia needs to be used under the diagnosis of traditional Chinese medicine, and should not be used blindly by oneself to avoid causing damage.