The active ingredients isolated from Cistanche include iridoid and phenylpropenoid glycosides, such as acetoside (also called verbascoside, named for Verbena, from which it was first isolated), echinacoside (also found in the Western herb echinacea), and cistanoside (named for cistanche). The active constituents of cistanche are quite similar to those of another kidney tonic, rehmannia, which is a yin nourishing tonic. In fact, all three of these glycosides are also found in rehmannia, along with its primary iridoid glycoside, catalpol. Rehmannia and cistanche are both rich in sterols, such as daucosterol and sitosterol. Thus, it could be that the "gentle" nature of cistanche as a yang tonic is due to having ingredients that also nourish yin.
The uses of cistanche have evolved over nearly 2,000 years. Cistanche was described in the oldest surviving herb classic, Shennong Bencao Jing (ca. 100 A.D.), as follows:
Cistanche is salty. It mainly treats the five taxations and seven damages, supplements the center, eliminates cold and heat, nourishes the five viscera, strengthens yin, and boosts essence qi.
Although classified as salty, cistanche actually has little salty taste and is somewhat sweet and slightly bitter. The "five taxations and seven damages" refer to an ancient concept for adverse influences that serve as a basis for deficiency of fluid essences (deficiency of blood, yin, jing); there can be several causes including genetic problems and the effects of debilitating diseases. As a tonic, cistanche is mentioned here as supplementing the center (stomach/spleen), nourishing the five viscera (five zang organs), strengthening yin, and boosting the essence.
Cistanche is not frequently included in ancient formulas. It mainly appears in large tonic formulas that were described during the Ming Dynasty or later. One of the oldest formulas containing cistanche that comes down to us today is a 14-herb combination called Huan Shao Dan (Youth Returning Pill), designed to restore kidney essence and, thereby, help restore youth and prevent further degeneration with aging (2). Its origins are obscure and attributed to various authors, dating back to the Song Dynasty or earlier. It is today sometimes called Lycium Formula, used in Japan and Taiwan as a tonic for kidney deficiency syndromes. Using today's classification of herbs in the Chinese Materia Medica, only three of its ingredients are yang tonics (cistanche, eucommia, and morinda) that might be directly associated with the modern approaches to treatment based on using multiple yang tonic herbs.
One of the Ming Dynasty formulas with cistanche-and one of the few in which it is a main ingredient-is Bushen Cishi Wan (Magnetite Pill for Nourishing Kidney) from Shenshi Yaohan (Precious Book of Ophthalmology) by Fu Renyu published in 1644 (the last year of the Ming Dynasty). The formula is a pill comprised of equal parts of five herbs: cistanche, cuscuta, magnetite, chrysanthemum, and haliotis. This text also yielded the better known vision formula Mingmu Dihuang Wan (Rehmannia Pill to Brighten the Eyes), which similarly includes the eye nourishing ingredients chrysanthemum and haliotis.
Thus, in general, cistanche is utilized in formulas for tonifying the kidney and used for disorders associated with aging and decline of kidney essence. Though classified as a yang tonic, it has yin nourishing qualities. These attributes are also associated with cuscuta seed, which is classified with the yang tonics but has yin nourishing qualities and mild action. Cistanche and cuscuta are frequently combined in formulas.