Yin Qiao, based on Honeysuckle and Forsythia Powder (Yin Qiao San), is a well-known formula addressing the early stage of an external invasion. Defensive (Wei) Qi is responsible for protecting the body from external invasion. It circulates in the outer layers of the body, between the skin and the muscles and its function is to prevent exterior influences such as Wind, Heat and Cold from penetrating to deeper levels of the body. When an exterior Wind Heat condition is not addressed properly, the exterior influence can penetrate to the Lesser (Shao Yang) level, midway between the Interior and the Exterior, where it might remain entrenched. This usually will manifest as an internal Heat or Damp Heat condition. The resulting Heat or Damp Heat can further damage the Qi and Yin of the body, leading to deficiency states that can leave one open to further invasions. By releasing the Exterior at the Wind Heat stage, this pattern is mitigated before penetrating more deeply. Yin Qiao is an appropriate formula to use with this presentation, as it helps invigorate and bring to the surface the Defensive Qi. It releases the Exterior, disperses Wind Heat, and clears Heat from the Lungs. The chief herbs in this formula, Honeysuckle flower and Forsythia fruit dispel externally contracted Wind Heat and clear Heat from the Lungs. Platycodon root and Burdock fruit, two of the deputies, are frequently combined to specifically address stagnation. Platycodon root opens up, disseminates, and raises Lung Qi, dispels Phlegm, benefits the throat, and directs the actions of the other herbs to the Upper Burner. Burdock fruit disperses Wind Heat and benefits the throat. The other deputies are Chinese mint herb and prepared Soybean seed. Chinese mint herb facilitates the dispersal of Upper Burner Wind Heat, cools and clears the eyes and the head, and soothes the throat, while prepared Soybean seed releases the Exterior. Schizonepeta herb releases the Exterior and dispels Wind. Lophatherum herb and Phragmites rhizome clear Heat, support healthy urination, clear Damp Heat and generate fluids. Chinese licorice root and rhizome tonifies the Spleen Qi, moistens the Lungs, clears Heat and harmonizes the actions of the other herbs in the formula. Similar Exterior releasing formulas include: Calm Breath Formula clears Heat from the Lungs caused by an external invasion, moistens Lungs and transforms Phlegm; Blue Green Lung Formula releases an exterior Wind Cold invasion, warms the Lungs and transforms Phlegm; Great White Lung Formula clears a Wind Heat or Wind Cold invasion transforming into Heat in the Lung and clears Phlegm; Lung Qi Release warms and releases an exterior lingering invasion. Initial Defense clears exterior Heat. Combine with Antiphlogistic Formula or Zhong Gan Ling to more strongly clear Heat and expel Wind. ORIGINS AND DEVELOPMENTYin Qiao is taken from the classic book, Systematic Differentiation of Warm Disharmonies, by Wu Ju-Tong.
