When decocting Chinese medicine, some people believe that the stronger the concentration of the decoction, the better the effect. However, this is a misconception. A high concentration of Chinese medicine decoction does not necessarily mean better results.
In the Chinese medicine classics, there is a record about decoctions: "Decoction is used to eliminate serious diseases." This means that decoctions have a cleansing and purging effect, and are most suitable for diseases with obvious yin-yang imbalance or long duration. How to decoct Chinese medicine decoctions has always been highly valued by medical experts throughout history. Xu Lingtai said in "The Origin and Development of Medicine": "The method of decocting medicine is the most important factor in determining whether the medicine is effective or not." Therefore, it is crucial to decoct Chinese medicine properly in order to eliminate diseases and fully exert the medicinal effects.
Decoction is the process of continuously releasing and dissolving the active ingredients in Chinese herbal medicine tablets. When the concentration of active ingredients in the tablets reaches a balance with the decoction, the diffusion process stops. If the decoction continues in order to make it "thicker and less in quantity," not only will the active ingredients in the medicine not be released further, but non-active ingredients (such as resins, gums, pigments, and other large molecular compounds) may continue to dissolve. This can cause a decrease in the concentration of active ingredients in the decoction due to evaporation, and even lead to the destruction of the active ingredients at high temperatures for a prolonged period, thereby reducing the medicinal effects.
In addition, decocting for too long can result in a thick and turbid decoction. Overly concentrated decoctions can intensify the bitterness, making it difficult for patients to take the medicine. It can also cause side effects such as nausea and vomiting after taking the medicine. Therefore, in order to ensure the proper efficacy of Chinese medicine, it is necessary to decoct for a certain period of time according to the conventional method. For example, for exterior-releasing medicines, decoct for 10-15 minutes after boiling, and decoct for 10 minutes for the second time; for nourishing medicines, decoct for 30-40 minutes after boiling, and decoct for 25-30 minutes for the second time; for general medicines, decoct for 20-25 minutes after boiling, and decoct for 15-20 minutes for the second time. It is advisable to decoct twice for all types of decoctions. After decocting the herbal medicine, it should be filtered while hot and squeezed dry to minimize the residual amount of the liquid in the dregs. Medicines containing volatile components, such as peppermint, perilla leaf, patchouli, and pelargonium, do not need to be decocted at a high concentration. During the decoction process, the lid must be kept on to prevent the evaporation of active ingredients. Clearing heat medicines such as honeysuckle flower and chrysanthemum, as well as aromatic medicines like amomum fruit and aloeswood, also do not need to be decocted at a high concentration. Some tonifying medicines require high concentration decoction, but the specific degree of decoction and the amount to use should be determined by a traditional Chinese medicine practitioner based on the patient's condition. It is not advisable to increase the amount or prolong the decoction time without authorization. Some Chinese medicines containing saponins, such as sand ginseng, notoginseng, achyranthes root, licorice, and balloonflower root, will start to boil before reaching 100°C, resulting in the phenomenon of "false boiling." If the medicine is taken off the heat at this time, the active ingredients in the herbs will not dissolve fully, and the medicinal effect will be affected, failing to achieve the desired therapeutic effect. Therefore, attention should be paid during the decoction process.
Each time a decoction is prepared, the amount of filtered liquid should not be less than 180 milliliters (about nine-tenths of a bowl). If it is for children, the amount of filtered liquid can be reduced to around 120 milliliters due to the lower dosage.
