[Source]

“Discourse on Cold Damage” (Shang Han Lun)

 [Composition]

Cinnamon Twig, White Peony Root, Licorice, Raw Ginger, Jujube, Kudzu Root
(6)

 [Classification]

<Blood Tonic>: White Peony Root

<Spleen and Middle-Jiao Tonic>: Licorice, Jujube

<Exterior Releasing (Cool)>: Kudzu Root

<Exterior Releasing (Warm)>: Cinnamon Twig, Raw Ginger

[Formula Meaning]

“Essentials of Internal Medicine” (Nei Tai Fang Yi): Kudzu root is neutral in nature, capable of dispelling wind evil and releasing the muscle layer. It is used here as a guiding herb; supplementing the function of Guizhi Tang to address the prevalent wind evil in the muscle layer. “Collected Notes on the Treatise on Cold Damage” (Shang Han Lun Ji Zhu): Guizhi Tang is used to release the evil qi in the muscles of the Taiyang channel; adding Kudzu Root, it promotes the circulation of Qi in the meridians and treats evil qi in the Taiyang channel. “Selected Notes on Ancient Formulas” (Gu Fang Xuan Zhu): Guizhi Jia Gengen Tang treats evil that comes from the Taiyang and reaches the Yangming. Kudzu Root is added to the formula to counteract the Yangming evil. Since the Taiyang evil has not yet dissipated, Guizhi Tang is still used to intercept it. However, the doses of Cinnamon Twig and White Peony Root are each reduced by one liang, preventing Kudzu Root from lingering in the Taiyang and allowing Cinnamon Twig and White Peony Root to enter the Yangming to moderate excessive sweating. Its function of promoting Yang and benefiting the Ming is indeed thorough. “Explanations of Formulas in the Treatise on Cold Damage” (Shang Han Lun Fang Jie): This formula is composed of Guizhi Tang with reduced doses of Cinnamon Twig and White Peony Root, plus one additional herb, Kudzu Root. The original text includes Ephedra, which is inconsistent with the principles. It should follow the opinions of Lin Yi, Zhu Geng, and others, and also refer to “Yu Han” to delete Ephedra. Zhang Zhongjing used Kudzu Root for stiff neck and back, likely considering Kudzu Root as a specific herb for this condition. Kudzu Root has the effects of releasing the exterior, relieving heat, and detoxifying. Zhang Zhongjing used it to treat stiff neck and back, and later generations used it to promote eruption and relieve heat, which is the rationale behind it.

 [Functions]

Induce sweating, release muscles, dispel wind, promote body fluids, and relax tendons.

 [Efficacy]

External contraction of cold and wind, fever, sweating with aversion to wind, stiff and uncomfortable neck and back, thin white tongue coating, superficial and slow pulse. This formula targets symptoms of Guizhi Tang with tension from the neck to the back. Kudzu Root has the effect of relaxing muscle tension.

 [Indications]

Colds, headache, wind-cold type scapulodynia (shoulder pain).

 [Mnemonics]

Formula name (Guizhi Tang + Kudzu Root).