["Efficacy Theory" may help to explain characteristic advantages of traditional Chinese medicines].

This article proposes the "Efficacy Theory" hypothesis of the traditional Chinese medicines (TCMs): TCMs take effects and weaken toxicities through the additive effects of numerous effective forms (including their constituents or/and metabolites) on a same target, the synergistic effects based on the overall action of the additive effects on individual targets and their toxicities scattering effects. A TCM may include approximately 1000 constituents and each constituent may produce about 100 metabolites in vivo after oral administration. Numerous effective forms of incalculable constituents and their metabolites could work like a "army group" together. When the quantity of a specific target molecule is larger than the pharmaceutical molecules, the molecules of different kinds of effective forms could combine with the target molecules successively, to exert the additive effects. When the target molecules are mostly occupied ("target most spaces occupied"), this TCM begins to work. The additive effects maybe exert not only in concentration but also in a time order way, which gives a sustained efficacy of TCM. The additive effects and the toxicities scattering effects are resulted from the same effective groups and not identical toxic groups among different effective form molecules. The "toxicities scattering effect" can be used to explain the non-toxic TCMs, but not fit for toxic TCMs. The efficacy theory showed that the variety of constituents and metabolites may participate in the process of pharmacodynamic actions, including the additive effects, synergy effects and toxicities scattering effects, which may be useful for explaining and developing the characteristic advantage of the TCMs. The questions we need to study or confirm are as follows: What are the TCMs' pharmacodynamic substance basis and mechanism made up of Why are toxicities of most TCMs' smaller How is the TCMs' "Efficacy Theory" which reflects characteristic advantage of TCMs applied in the research and development of new drugs.