It is a testament to the genius of Sun Si Miao, its creator, that a formula as complex as Spine Lithe (Du Huo Ji Sheng Tang) is still in popular use. It is an even greater testament to his perspicacity that it contains two smaller formulas that would become among the most utilized herbal formulas. These two smaller formulas are Four Substances (Si Wu Tang), the quintessential Blood tonic formula, and Four Gentlemen Decoction (Si Jun Zi Tang), the quintessential Qi tonic formula. Three of the herbs of Four Substances are found in this formula. They are White peony root, prepared Rehmannia root and Sichuan lovage rhizome. The herbs in Four Gentlemen Decoction represented here include Chinese red ginseng root and rhizome, Chinese licorice root and rhizome and Poria. The Kidney-tonifying herbs of Spine Lithe include Eucommia bark, Loranthus herb and Cyathula root. Eucommia astringes and tonifies Kidney Yang, while Cyathula root astringes and tonifies Kidney Yin. Loranthus herb expels Wind Cold Damp while supporting the Kidneys. Curculigo rhizome, Pubescent angelica, Large-leaf gentian root and Siler root expel Wind Cold Damp from the channels, allowing Blood and Qi to course to the body periphery. Spine Lithe retains much of the original architecture, but has some minor variations. Notopterygium root and rhizome has been added to extend the Wind-dispersing effects of the formula to the upper back and neck, instead of just the low back. Use of Cyathula root in place of Achryanthes and Dong Quai confers a Blood-moving effect while still nourishing the tendons. Prepared Rehmannia root is used in place of fresh Rehmannia because of its extra Blood- tonifying and warming effects. Curculigo rhizome is used in place of Asarum to dispel Wind Cold Damp, while further supporting the Kidneys and the bones.
