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Two Ultimate Pill

by Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon

Erzhi Wan is a two ingredient (er = two) formulation that is frequently mentioned in modern Chinese medical literature. The pair of herbs-ligustrum and eclipta-are sometimes used as is, but more commonly they are incorporated into somewhat larger prescriptions. The formula name, which might be better translated as Two Solstices Pill, refers to when the herbs are routinely collected: each of the herbs is picked near the time of the solstice, the ultimate manifestation (zhi = furthest point) of the annual cycle of yin and yang. Specifically, ligustrum is picked at the winter solstice (ultimate yin, the end of winter, before the weather warms) when its fruits are ripe, while eclipta is picked at the summer solstice (ultimate yang, at the end of summer, before the weather cools) while in flower.

The formula was recorded by Wang Ang in his 1682 A.D. publication Yifang Jijie (Collection of Medical Formulas). Wang remains a well-studied medical writer (see Appendix) who emphasized the teachings of the Jin-Yuan medical reforms. In this case, the formulation applies well to the School of Yin Nourishing, which held that yin always tended to be insufficient, especially with aging, so that it needed to be protected and restored. Erzhi Wan is a yin nourishing formula. According to Wang Ang, "Erzhi Wan supplements the lower back and knees, strengthens the sinews and bones, strengthens the yin and the kidneys, and blackens hair. It is inexpensive and greatly effective (1)." He also recorded in the same text another formula with different ingredients but similar indications called Qibao Meiran Dan (Seven Treasures Elixir for Beautiful Hair).

Many authors have commented on Erzhi Wan; for example, the description in Chinese Herbal Medicine Formulas and Strategies includes this commentary (2):

This formula is an elegant combination of two herbs. Ligustrum is a sweet, bitter, and cool herb that enriches the kidneys and nourishes the liver. Eclipta is a sweet, sour, and cold herb that nourishes the yin, benefits the essence, and cools the blood to stop bleeding. Together, they nourish the yin aspects of the liver and kidneys without being cloying.

The reference here to the absence of "cloying" is especially made in relation to the use of cooked rehmannia for yin deficiency syndromes; that herb is very sweet and rich, and can be difficult to digest. The authors point out that Erzhi Wan is often compared to Liuwei Dihuang Wan (Rehmannia Six Formula), stating that "although the two formulas are quite similar in usage, the latter is regarded as a slightly stronger formulation. Erzhi Wan is preferred when chronic bleeding is part of the presentation, and is considered by some to be superior in treating premature graying or loss of hair." Wang Ang also took an interest in Rehmannia Six Formula and presented a modification with schizandra added, called Da Qi Wan (Capital Qi Pill). The issue of the cloying nature of yin nourishing herbs (especially, rehmannia) and avoiding the problem is emphasized by Yang Yifang (3):

Ligustrum and eclipta are sweet and cold and enter the liver and kidney meridians. They can nourish the yin without any cloying side effects. They are suitable for treating dizziness, tinnitus, blurred vision, weakness in the back and knees, and premature gray hair due to liver yin and kidney yin deficiency. Since they are not cloying in nature, and have gentle and steady actions, they can be used for a longer period of time in chronic disease. Moreover, these two herbs are also suitable in conditions where the blood is deficient and there is slight heat in the blood.

Philip Sionneau (4) compares and contrasts the main actions of the two herbs, first indicating that both nourish the liver and supplement the kidneys, and then differentiating as follows:

  Eclipta Ligustrum
Cooling Action Cools the blood and stops bleeding Clears deficiency heat
Nourishing Action Enriches yin and blackens the hair, nourishes the lower and upper parts Nourishes liver yin and brightens the eyes; fills the essence, and blackens the hair

In Ten Lectures on the Use of Medicinals, Jiao Shude recommends strengthening Erzhi Wan by adding morus fruit (5):

Eclipta combined with ligustrum to form Erzhi Wan is often used for liver-kidney yin deficiency with premature graying of the hair and hair loss. The juice of morus fruit (mulberry) can also be added to the pill….Ligustrum combined with morus fruit and eclipta, made into a honey pill, and taken over a long period of time, is used for patterns of debilitated health and chronic deficiency detriment….Ligustrum combined with eclipta, morus fruit, ho-shou-wu, raw rehmannia, eucommia, dioscorea, and lycium is used to treat liver-kidney yin deficiency that manifests in premature graying of the hair, clouded or flowery vision, tinnitus, deafness, loosening of the teeth, yin deficiency heat, and deficiency pain of the lower back and knees.

These and other authors agree that rehmannia has a greater yin nourishing potential than Erzhi Wan, but that the combination of eclipta and ligustrum is suited especially to long term use, and to cases where digestive weakness makes it more difficult to consume rehmannia formulas. Also, there is general agreement that the yin nourishing effect of Erzhi Wan can be strengthened and improved by adding morus fruit.


Eclipta (Eclipta alba; see photo below) has oleanane saponins (triterpene glycosides) and wedelolactones (lactones named after being found in Wedelia species). Oleanane saponins are found in ginseng, jujube, and other tonic herbs as well as several cooling anti-inflammatory herbs; the wedelolactones are coumestans, a type of phytoestrogen. Eclipta is also used extensively in Ayurvedic medicine, as a treatment for liver diseases, skin disorders, and for premature graying of hair (often used topically in black sesame oil).

Eclipta alba and its saponins    
Eclipta alba and its saponins

Ligustrum (Ligustrum lucidum) has oleanolic acid and secoiridoid glycosides. Oleanolic acid is the base molecule of oleanane triterpenes (with glucose removed) such as those found in eclipta. It also has anti-inflammatory activity and has been used in treatment of hepatitis; secoiridoid glycosides have heat-clearing and anti-inflammatory activity; they are also main active components of gentiana species (e.g., longdancao and qinjiao), which are used in treating arthritis and hepatitis.

The "yin nourishing" and "hair blackening" actions of these ingredients are hard to explain based on the active components and our limited knowledge of their pharmacological properties. On the other hand, these herbs are apparently suitable for alleviating liver inflammation based on the existing studies.

The hair blackening action of the herbs might be based, in part, on a doctrine of signatures. The eclipta plant, when broken, exudes a blackish sticky juice; a common name for it is "ink plant (6)." Several other herbs for keeping the hair black are also dark colored: cooked rehmannia, shou-wu processed with black soybean, black sesame seeds, and psoralea. Ligustrum seeds also have a shiny black color when fresh.

Ligustrum lucidum and oleanolic acid    
Ligustrum lucidum and oleanolic acid


The original instructions for producing Erzhi Wan (wan = pill) was to render equal amounts of the two herbs to powder, then form into pills with honey (2). Modern versions, presented in the English-Chinese Encyclopedia of Practical Traditional Chinese Medicine (7), use extracts for part or all of the preparation. One version combines ligustrum that has been finely ground to powder with eclipta that has been extracted by decoction three times, the combined decoctions being evaporated to make a thick syrup, to which honey is added. The mixture is then formed into boluses as big as 15 grams each; the dosage is 1 bolus each time, once in the morning and once in the evening. The other preparation is Erzhi Gao (paste): the two herbs in equal amounts are decocted, the decoction is condensed, and then honey is added. The resulting thick syrup is taken in doses of 15 grams each time, 2-3 times daily. Hence, the forms range from powder of both herbs, to powder of ligustrum and extract of eclipta, to extract of both herbs. In making these honey preparations, it is common to use up to one-third honey by weight, so the dosing of herb materials appears to be on the order of 10 grams of powder or extract material each time, at least twice per day.


Wang Ang (1615-1697) was a medical reformer. He looked aghast at the poor condition of most of the medical literature of his era and considered that the form, language, and intent had to be adjusted. There were certain authors he respected, notably the Han Dynasty author Zhang Zhongjing (author of the Shanghan Lun, the most famous book of herb formulas and prescription principles); the Song Dynasty author Cheng Wuji (known for his study of promulgation of Shanghan Lun); and the Ming Dynasty author Li Shizhen (author of the Bencao Gangmu, the last great Materia Medica of the classical period, published in 1596 and distributed in the early 1600s, just before Wang Ang's birth), and he followed their examples. He is famous for having written a Materia Medica of his own (Bencao Beiyao) and two formula books (Tangtou Gejue and Yifang Jijie). Wang was a strong advocate of using pulse diagnosis (and other classical methods) to determine the flow in the conduits (meridians) and thought that it was important to understand which conduits were affected by each herb (the property known as "meridian entrance"). In keeping with this idea, he emphasized paying close attention to differential diagnosis. He compiled the Yifang Jijie "to make readers use formulas based on overall analysis of symptoms and signs, think of them according to clinical syndromes and not make erroneous use of reinforcement and elimination," pointing out that: "You can adjust formulas according to syndrome as well, and it is not difficult to choose formulas and use herbs even if you live in a poor and remote village (6)." This book presented 300 formulas that he collected and more that he had designed. The prescriptions were classified into 21 categories of therapeutic action, which were largely adopted as the categories used in modern books. As a result of his efforts, he is responsible for designing (or, at least, passing on) some herb prescriptions that are widely used today, including Longdan Xiegan Tang, Baihe Gujin Tang, and Jinsuo Gujing Tang.

Wang Ang lived at a time when missionaries from the West were beginning to establish a base for Western medicine. Born in Anhui, he moved to Suzhou as an adult, thus living near Beijing, which had been a destination for the missionaries. He had a favorable view of Western medicine, namely that it offered some new insights (e.g., that the mental functions took place in the brain rather than the heart) and also provided additional treatment strategies, but it did not appear to replace Chinese medicine.

Paul Unschuld, in his book Medicine in China: A History of Pharmaceutics (7), follows the development of various Bencao works, and commented extensively on Wang Ang's work, including some quotes from introductory remarks to Wang's books. The relevant segment is reproduced here at length:

Wang Ang can probably be considered the most successful medical writer of the Qing period. Even today, a large number of his works are widely circulated among practitioners of traditional Chinese medicine. In addition to the drug work Bencao Beiyao, the Tangtou Gejue (Lyrical Prescriptions), and the much more extensive Yifang Jijie could be mentioned here as two of his well-known prescription works.

Wang Ang's lasting success may have two explanations. First, he utilized an easily understood language. His works could be penetrated by those lacking a thorough education. Second, he apparently created the most advantageous combination of the two earlier traditions: the main Bencao tradition (deriving from Shennong Bencao Jing) and the Jin-Yuan traditions. Wang Ang repeatedly expressed his views on this matter; in the introduction to the Yifang Jijie, he emphasized the necessity of a theoretical foundation for the use of medications:

The prescription literature, both old and new, is quite extensive, and yet always the commentaries that precede the prescription state only: "cures this and/or that illness!" Explanations of the underlying causes of the illness are always lacking, as is information on which conduits are affected by the illness. In addition, within the individual prescriptions, advice is given only to use this and/or that drug. However, information is always lacking on the effects of nature, taste, or which of the various conduits are penetrated, and thus, on the basis for the drug's abilities to cure certain illnesses. In fact, the works dealing with prescriptions were therefore written in a senseless manner, and the superficial capabilities of the common medical practitioners can be viewed as being characterized by ignorance. They limit themselves to treating living illnesses with dead prescriptions and not infrequently shower the world with their mistakes, thereby causing harm to mankind.

By contrast, during the Song Period, Chen Wuji was the first to study the works of Zhang Zhongjing. He placed the explanation of illnesses at the beginning and clarified the effective properties of drugs, so as to enable the reader to understand from the beginning to end.

That Wang Ang was not restricted to certain theories and kept an open eye for practical problems is indicated by the following excerpt from the introduction to the Bencao Beiyao:

In the descriptions of drug indications by earlier authors, general details are more frequent than differentiating ones. Thus, for example, among the drugs that cure mucous diseases are those suitable for the treatment of dry mucus and those suitable for moist mucus. But all works include only the information that mucous afflictions can be eliminated with the drugs in question. Drugs for headaches, as a further example, can be subdivided into those directed against headaches caused by internal sources and those caused by external sources. In all works, however, only the following can be read: "they cure headaches." But these are symptoms with opposite causes and cannot be approached in an undifferentiated manner. These are only two examples; the others can be deduced in similar manner. In addition, I would also like to mention that it is only stated which drugs are suitable for use with specific illness. But references to which illnesses must not be treated with these drugs are lacking. For this reason, I have taken such incompleteness into account here, supplementing such material with detailed commentaries. In this manner, I have avoided deceptions.

Cover and sample page of Wang Ang's Bencao Beiyao, an illustrated 1740 edition, volume 1 of 6 volumes.    
Cover and sample page of Wang Ang's Bencao Beiyao, an illustrated 1740 edition, volume 1 of 6 volumes.

The thoughts that motivated the author during the compilation of the Bencao Beiyao, as well as the models and the points of emphasis, are described in the preface:

The most important thing in medicine is the examination of the pulse. Only the person who can correctly recognize the different movements in the vessels and the manifestations of illnesses that appear in them is able to differentiate whether it is a question of depletion or repletion. Otherwise, the assaults against illnesses and the treatments for the replenishment of depletions are senseless, and instead of achieving a long life, the result is usually an early death. The second most important thing in medicine is the necessity of clearly understanding the properties of drugs. If, for example, an illness is present in a specific conduit, a very specific drug must be administered. It is also possible that the illness located in this conduit can spread to other conduits; a treatment of replenishment must then be carried out upon the associated mother organ or a treatment of drainage on the receptive child organ-weakness must be supplemented and violence checked! The correct method of action is based upon many principles, and one cannot simply emphasize one alone as binding. If a person is incapable of uniting individual details, penetrating generalities, analyzing subtleties, and understanding the mysterious, he will not succeed in achieving brilliance, but he will approach evil and stray from the correct path. In earlier times, it was aptly said: "The use of drugs is similar to the employment of soldiers: one must really be careful!"

From antiquity to the present time, several hundred authors have written Bencao works. None of them, however, surpasses the Bencao Gangmu of Li Shizhen in either spirit or accuracy. The examinations and studies expressed in this work are, at the same time profound and extensive; formation is comprehensive and clear. For this reason, I admire the attitude of this man and would like to speak praisingly of "extreme perfection." However, the chapters and volumes were written in such numbers that it is difficult to study the work completely during the course of a lifetime. Furthermore, it is rather cumbersome to bring along when traveling by boat or carriage. It is indeed an all-embracing work, but that which is essential cannot be recognized immediately….

For more than three years I collected the Bencao works of all authors; from comprehensive reading I returned to a concise presentation. I selected a total of 400 drugs suitable for use and arranged them in a small volume. In this work I discussed which drugs penetrate which specific conduits, and which affliction they then relieve. For this one must be knowledgeable about the nature, taste, appearance, and color of the drugs, since these properties are considered the foundations of the main curative effects. In between I have added the profound and broad meaning [of the relationship of herbs in a formula by] "extreme aversion and common action, and of the formation of resistance, and of mutual aid," upon which the people of antiquity based the use of drugs. Following the drug descriptions, I have added information concerning place of origin, method of preparation, and incompatibilities. I have placed the ten types of prescription combinations and the treatises on diverting and penetrating properties and the depletion-restoring and repletion-relieving characteristics before the drug descriptions. In this manner, I have described the effectiveness of the drugs but have also elucidated their possible disadvantages, so that people will realize it while reading. As a result, the use of this work and the drugs it describes do not lead to mistakes. It can probably be said that, on the one hand, my work is comprehensive but that on the other hand, the essential elements can be recognized. Intelligent scholars can use the work as a basis for their investigations, for the essence and subtleties of medicine can, for the most part, be taken from it….By using this text, the correct way to the works of our ancestors is achieved.

A chapter entitled "Summary of the Significance of Drug Properties" is placed before the main part of the Bencao Baiyao. In this chapter, Wang Ang offered the reader nearly the entire spectrum of the most important theoretical foundations of pharmaceutics. He explained the sense and utilization of the doctrines of the five tastes and five colors, of the yin and yang correspondences, and of the mode of operation of drugs in the body. The contents of the individual monographs in the main section were already indicated by the author himself in the preface reproduced above. They contain, like the preceding works of this tradition, a detailed consideration of the Jin-Yuan doctrines. Originally, the Bencao Baiyao was not illustrated. Only in later editions were illustrations added for most of the drugs. Wang Ang himself, at the age of eighty, completed a revised edition of his work, expanded in comparison to the original by sixty drug descriptions.


  1. Ellis A, Notes from South Mountain, 2003 Thin Moon Publishing, Berkeley, CA.
  2. Bensky D and Barolet R, Chinese Herbal Medicine: Formulas and Strategies, Eastland Press, Seattle, WA
  3. Yang Yifang, Chinese Herbal Medicines Comparisons and Characteristics, 2002 Churchill Livingstone, London.
  4. Sionneau P, Dui Yao: The Art of Combining Chinese Medicinals, 1997 Blue Poppy Press, Boulder, CO.
  5. Mitchell C, et al. (translators), Ten Lectures on the Use of Medicinals from the Personal Experience of Jiao Shude, 2003 Paradigm Publications, Brookline, MA.
  6. Smith FP and Stuart GA, Chinese Medicinal Herbs, 1973 Georgetown Press, San Francisco, CA.
  7. Xu Xiangcai (chief editor), The English-Chinese Encyclopedia of Practical Traditional Chinese Medicine (vol 3, 9), 1989 Higher Education Press, Beijing.
  8. Chen Ping, History and Development of Traditional Chinese Medicine, 1999 Science Press, Beijing.
  9. Unschuld PU, Medicine in China: History of Pharmaceutics, 1986 University of California Press, Berkeley, CA.

September 2003