The Rules of Compatibility Between Herbs and Formulas—Reflections on TCM Cancer Research by Zhou Zhiyuan, Part 3

Using a single herb to treat disease is an ideal state, but it is not easily attained. So the common situation is that a single TCM prescription contains multiple herbs.

When various herbs are combined and used together according to certain rules, that is the compatibility of Chinese herbs. The rules of herb compatibility are the foundation of TCM prescription composition.

A formula made of a single Chinese herb is called a single-substance formula (danfang). A formula composed of two or more Chinese herbs combined according to compatibility rules is a Chinese herbal compound (fufang). Through history there have been many highly effective single-substance and compound formulas that solve many problems.

Here I extend the concept of compatibility a little: compatibility rules can be applied not only between herb and herb, but also between formula and formula, and between formula and herb.

When several different proven formulas are paired and used together according to compatibility rules, they often achieve an effect that a single proven formula cannot.

This method of compatibly using two or more herbal compounds traces back as early as to the Medical Sage Zhang Zhongjing; a great many of his formulas are used in combination.

For example, Mahuang Guizhi Ge Ban Tang takes half of Mahuang Tang and half of Guizhi Tang and combines them, used to resolve the Mahuang-Guizhi half-and-half pattern, whose symptoms lie between the Mahuang Tang pattern and the Guizhi Tang pattern. Another example: when a patient has both a Guizhi Tang pattern and a Xiao Chaihu Tang pattern, one combines Guizhi Tang and Xiao Chaihu Tang into Chaihu Guizhi Tang to solve the problem.

Many physicians of later generations excelled at combining several proven formulas to solve problems that a single prescription could not.

Many famous formulas were even formed precisely by such merging. For example, the blood-tonifying Siwu Tang and the qi-tonifying Sijunzi Tang, merged into one formula, become the qi-and-blood double-tonifying Bazhen Tang.

Mr. Shi Jinmo, one of the four great famous doctors of the capital, liked very much to combine several prescriptions; so his formulas were all very large.

Shi Jinmo's disciples even wrote a book of the small prescriptions he commonly used—Shi Jinmo's Herb Pairs. The so-called herb pairs in this book are themselves small compounds. When Mr. Shi used them clinically, he often combined these small compounds, attaining remarkable effects.

The veteran TCM doctor Jiao Shude was also a master in this regard, though Dr. Jiao liked to call his large prescriptions, assembled from several small ones, the "combined formula of party A and party B"; but their gist is no different from the compatible use of prescriptions.

I do not know whether any other TCM doctor has previously put forward the idea of the compatible use of TCM formulas; perhaps someone has, but I have not read the relevant literature.

Here I will provisionally claim this idea as my own. The reason I raise this concept is not to be novel or different—there are not so many novelties and differences in medicine worth making a show of; the more long-tested the clinical experience, the more precious it is.

The reason I raise this concept is to clarify the rules of compatible formula use, so that future students of medicine can better master the craft of clinical formula composition.

My ideal, through this book, is to let my readers, from now on, be able to compose their own formulas to solve their own problems—whether or not they have studied TCM before.

TCM formula composition is not mysterious. One can compatibly pair herb with herb to form a formula; one can compatibly pair formula with formula to form a larger compound; and one can also combine a formula with certain herbs to solve complex problems.

This rule of combination is called, in TCM, the rule of compatibility. There are seven common compatibility rules, known in TCM as the seven emotions (qiqing): single action (danhang), mutual reinforcement (xiangxu), mutual assistance (xiangshi), mutual restraint (xiangwei), mutual detoxification (xiangesha), mutual antagonism (xiang'e), and mutual incompatibility (xiangfan).

As for single action, most physicians take it to mean using a single herb to treat disease—for example, Dangshen Tang (Ginseng Decoction) to rescue a patient with massive bleeding, or single-herb Qingjin San to treat lung fire.

However, some scholars hold that single action means that, in a prescription composed of many herbs, one herb addresses one aspect of the problem and another addresses another, the two being in a parallel or equal relationship; Professor Zhang Tingmo, for one, holds this view.

I personally think the latter view is more appropriate. In this book I will also explain my philosophy of composing formulas and treating disease according to the latter view.

Mutual reinforcement means that herbs of similar properties, used together, strengthen the original effect. For example, Gypsum paired with Anemarrhena, Moxa resin (Ruxiang) paired with Myrrh (Moyao), Sparganium (Sanleng) paired with Curcuma (Ezhu), and centipede (Wugong) paired with scorpion (Quanxie), all enhance each other's effect.

When two or more herbs of similar properties are used together, they often achieve an effect that a single herb, even in large dose, cannot. For example, centipede and scorpion used together, 0.5 g each, are more effective than 10 g of centipede alone or 10 g of scorpion alone.

So using herbs that mutually reinforce one another can reduce the amount used, lower the cost, and at the same time raise the clinical efficacy.

Mutual assistance means that, when two or more herbs sharing some property or effect are used together, one herb plays the principal role and the others the assisting role, and the assisting herbs enhance the effect of the principal herb. For example, Astragalus and Poria used together: Poria enhances Astragalus's effect of supplementing qi and disinhibiting water.

Mutual restraint means that when a toxic herb is used together with another herb, the other can reduce its toxicity. For example, fresh ginger can reduce or eliminate the toxicity of raw Pinellia; this is called Pinellia fearing ginger.

Mutual detoxification means that one herb can reduce or eliminate the toxicity of another. In the case above, Pinellia fearing ginger, reversed, is called ginger detoxifying Pinellia. So mutual restraint and mutual detoxification are a pair of relative concepts.

Mutual antagonism means that when two herbs are used together, one reduces the effect of the other, or even makes that effect disappear entirely. For example, ginseng "antagonizes" radish seed (Laifuzi), because radish seed weakens ginseng's qi-supplementing action.

So two mutually antagonistic herbs are best not used together; but if some herb, taken in excess, causes a severe side effect, one can use an antagonistic herb to detoxify.

Take the common problem of "ginseng going to the head"—that is, taking too much ginseng and being poisoned. At such a time one can use radish seed or radish to detoxify. When my father was young, he ate chicken stewed with ginseng and developed "ginseng going to the head"; he felt unbearably hot and restless, and only after eating large amounts of white radish did he feel much better.

Mutual incompatibility means that two herbs used together can produce or intensify a toxic or adverse reaction—for example, the commonly cited TCM "eighteen incompatibilities" and "nineteen mutual restraints," which are typical examples of mutual incompatibility.

However, the scientific validity of the eighteen incompatibilities and nineteen mutual restraints has always been disputed. Many classic famous formulas regularly use herbs from the eighteen incompatibilities without obvious toxic side effects.

I myself occasionally use herb pairs from the eighteen incompatibilities and have not seen obvious side effects. On this point, further research is still warranted. But generally speaking, one should be cautious when using mutually incompatible herbs.

Combining herbs cannot really be a mere stacking of ingredients, used at random. Only by following these rules of medication can one achieve the goal of safe and effective use of herbs.

These seven rules of herb compatibility, summarized by the ancients, basically cover every aspect of combining herbs. These compatibility rules come from experience and intuition, not from metaphysical fancy. Even in modern medicine, various drugs are often used in combination, and roughly speaking, combining them also needs to follow these rules; otherwise one cannot meet the standard of safety and effectiveness.

These seven compatibility rules can also be applied to combining formulas. A formula, in a certain sense, is itself a kind of herb; two or more formulas can absolutely be combined according to these rules to strengthen efficacy.

For example, I myself often combine water-disinhibiting, swelling-relieving formulas such as Huangqi Fangji Tang with bloat-treating formulas such as Houpo Banxia Shengjiang Gancao Renshen Tang, and further combine them with qi-moving formulas such as Jiangjiang San, to treat various patients with ascites and pelvic effusion—taking the effect of solving multiple problems at once when they are used together. Such a combination is often far more effective than a single formula.

Sometimes a patient's condition is complex, presenting multiple formula-patterns. For example, if the patient shows both the "stiff neck and back," "spontaneous sweating," "aversion to wind," and "spontaneous diarrhea" of Guizhi Jia Gegen Tang pattern, and also the bitter mouth and dizziness of a Chaihu Tang pattern, I combine the two formulas to solve the patient's problem.

The conditions we meet in practice are always far more complex than those in the books. So one cannot treat disease by reading mechanically from the textbook; that is bound to fail.

A physician should memorize the effects of a large number of formulas and herbs, so that in clinical application, when a problem arises, he can, based on the various symptoms the patient presents, find the one or several corresponding formulas, and then judiciously use one or several of them in combination. Only thus can one guarantee clinical efficacy.

In this book, apart from the theoretical part, which covers a small amount of the principles of TCM medication and formula composition, the rest will introduce, in large quantity, the properties of each herb and the functions of the proven formulas.

The book is expected to introduce 300-500 Chinese herbs that may be used in treating tumor diseases, and 1000-2000 proven formulas for solving oncology problems. Both herbs and formulas will be introduced by category, according to their effects, for readers to look up.

I will also use case records to explain how I, and other doctors, composed formulas and selected herbs in the clinic to solve patients' problems. The ultimate goal is to enable readers to master the TCM craft of composing formulas and selecting herbs, so as to resolve the common complications of cancer patients and control the progression of their disease.

Readers must remember: no two leaves in the world are identical, and there will never be two identical patients; every patient is a unique individual. Although there are commonalities in treating different patients, there must also be differences. In treating disease, one must firmly remember that evidence-based medication is what matters most.

As for composing formulas, one can oneself combine, according to the compatibility rules introduced in this article, those proven formulas and Chinese herbs that have been repeatedly shown effective from ancient times to today. As long as one keeps a firm grip on the patient's various signs, finds the corresponding formulas and herbs, and combines them into a prescription, one can in most cases relieve the patient's condition, and even solve the patient's problem.

When a physician prescribes and uses herbs, once he abandons the principle of seeking truth from facts and seeking evidence, and sinks into the metaphysical talk of the various differentiation methods without coming out, that, for the patient, is a disaster.