The empirical knowledge passed down through TCM practitioners



The central tenet of Chinese medical thought is that the whole body should be kept in harmony. The theory of Yin Yang and the Five Elements are two ways of expressing this system harmony. This means that each organ of the body not only must perform well, but also must keep in balance with the rest. When one organ is not functioning, as it should, it will affect the overall performance of the others. TCM seeks to restore the body to a condition of balance using a method called dual modulation.

In pharmacological terms, dual modulation is when a drug (which commonly are herbal prescriptions in TCM) possesses a dual character. This means that when the body is in an unbalanced state, the same drug can be used to cause the body to go from a hyper-functioning to a normal state, or from an under-functioning to a normal state, with no adverse effects.


Many Chinese medicines have dual modulation characteristics. TCM has unique theories about this, categorizing the regulating properties of the medicinal substance into eight actions; "ascend and descend", "cold and heat production", "yin and yang", "reinforce and reduce", "excrete/drain and astringent", "dry and moisture", "activate and stop or slow down circulation", and "dissolve and gather". These actions relate to the drug's character and taste, quality, combination, processing methods and administration method.

Four Important Concepts of Dual Modulation

Dual modulation of particular herbs and medicinal substances is possible because of four important concepts. These are:

1.Herbs contain multiple active ingredients, which can have opposite effects on the body.

2. Different amounts of the same herb or medicinal substances can have opposite effects on the body.

3.The body's adaptation ability can allow herbs to work differently in times of stress or illness.

4. Different processing or preparation methods can bring about different healing effects of the same herb or medicinal substance.


By understanding the dual modulation effects of single herbs on the body, you can see how it becomes even more difficult to predict how the complex interactions of several herbs in one formula will affect the body.



The interactions between active ingredients contained in the herbs, dosages of each ingredient and processing methods, all contribute to make a unique product that can have completely different effects from a similar formula if any of these things are altered. Furthermore, these formulas may react differently from person to person or on a body that is healthy, stressed or ill.


This is why the empirical knowledge passed down through the TCM practitioners and various TCM classics is invaluable. The practitioner's skill in knowing what herbs can be combined, in what amounts, and how they should be prepared cannot be overlooked. This knowledge, combined with today's new scientific methods, help us to identify new active ingredients and understand how best to prepare and combine herbal ingredients to make even better TCM formulations for health maintenance.


By understanding the concept of dual modulation, you can understand why there is such variety in the efficacies of similar products. It is also essential to understand this concept in order that TCM formulas can be applied appropriately for maximum health benefits.


These and other Traditional Chinese practices all form part of TCM, each adding a little to the history and methodology of Acupuncture and Herbs.


Eca Brady is a fully licensed physician of Chinese Medicine BSc(Ac) MBAcC PGDip(CHM), practicing Acupuncture and Chinese Herbs from Harley Street, London. Make an appointment for an acupuncture or Herbs treatment and we can discuss how we can help you, to read more about Eca click here.




Extract from ShenNong

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