Traditional Chinese medicine decoction is one of the most commonly used dosage forms in Traditional Chinese Medicine for treating diseases. According to records, it was created around 1500 BC during the Shang Dynasty and is still in use today.
Many of us may know how to take traditional Chinese herbal decoctions, but not how to make them. Today, we will systematically explain how to prepare Chinese herbal decoctions.
When preparing traditional Chinese herbal decoctions, we need to pay attention to several points: the selection of cooker, the quality of water used, the intensity of decoction, and the decoction method.
Cooker
It refers to the vessel used for decocting Chinese herbal medicines. It can be a clay pot, earthenware pot, or enamel pot, but not an iron pot, copper pot, or aluminum pot. Metal vessels may undergo chemical changes with Chinese herbal medicines, affecting the efficacy of the decoction.
Water
In agrarian times, water from rivers, wells, rain, springs, or rice washing could all be used for decocting Chinese herbal medicines. Nowadays, water that meets drinking water standards can be used for decocting Chinese herbal medicines, such as tap water, distilled water, or spring water.
Intensity
It refers to the intensity of heat during decoction. For ease of distinction, it is divided into gentle heat (Wen Huo) and vigorous heat (Wu Huo). Gentle heat refers to low heat, slow fire, weak intensity, minimal temperature variation, and slow evaporation of water during decoction. Vigorous heat, on the other hand, refers to high heat, rapid fire, strong intensity, quick temperature rise, and fast evaporation of water during decoction.
Decoction Method
Before decoction, Chinese herbal medicines need to be soaked in water for 20 to 30 minutes (the water level must be higher than the level of the herbs). This helps to fully dissolve the active ingredients of the Chinese herbal medicines and shorten the decoction time.
If there is some sediment in the Chinese herbal medicines, they can be quickly rinsed with water to avoid soaking. Soaking may cause loss of water-soluble active ingredients in the Chinese herbal medicines, thereby reducing their efficacy.
When decocting Chinese herbal medicines, they are usually brought to a vigorous boil first and then simmered over gentle heat. The decoction time starts counting from when the herbal liquid boils.
Decoction of Chinese herbal medicines is done in two stages. After the first decoction, the liquid is poured out, and the dregs are retained. Half the amount of water used in the first decoction is added, and the Chinese herbal medicines are decocted again. The liquids from the two decoctions are strained, filtered, mixed, and taken in two doses.
The medicinal nature of Chinese herbal medicines determines the intensity and time of decoction. Usually, herbal medicines for relieving superficial symptoms and clearing heat should be decocted over high heat, brought to a boil and then continued for 3 to 5 minutes. Chinese herbal medicines for tonicity should be decocted slowly over low heat, bring to a boil and then continue to decoct for 30~60 minutes.
Some Chinese herbal medicines have unique textures and require special decoction methods, which may be specified in the Chinese medicine prescription. These methods include decocted first, decocted later, decocted with wrapping, separate decoction, dissolution, infused decoction, direct administration, and using decoction as a substitute for water.
Decocted First
Some Chinese herbal medicines with effective ingredients that are difficult to dissolve in water should be decocted first, such as shellfish drugs [ Mu Li (Concha Ostreae), Zhen Zhu Mu (Mother of Pearl), Shi Jue Ming (Concha Haliotidis) ], horn and bone drugs [ Shui Niu Jiao (Cornu Bubali), Long Gu (Fossilia Ossis Mastodi), Gui Jia (Carapax et Plastrum Testudinis), Bie Jia (Carapax Trionycis) ], and mineral drugs [ Shi Gao (Gypsum), Han Shui Shi (Glauberitum), Ci Shi(Magnetitum) ].
These drugs are hard in texture and should be crushed and decocted for 20 to 30 minutes before adding other drugs for decoction, ensuring full extraction of their effective ingredients.
Additionally, some highly toxic Chinese herbal medicines such as Fu Zi (Radix Aconiti Lateralis Preparata) and Chuan Wu (Radix Aconiti), should also be decocted first and decocted for a long time. It is advisable to decocted first them for 45 to 60 minutes before adding other drugs for decoction. Prolonged decoction can reduce their toxicity and ensure the safety of medication.
Decocted later
Some aromatic Chinese herbal medicines should be decocted later, such as Bo He (Mentha), Qing Hao (Sweet Wormwood), Sha Ren (Fructus Amomi), Chen Xiang (Aquilariae Lignum Resinatum), Bai Dou Kou (Fructus Amomi Rotundus), and Rou Gui (Cinnamomi Cortex). Prolonged decoction of these drugs will cause their effective ingredients to volatilize, thereby reducing their efficacy.
They should be decocted after boiling other drugs for 20 to 25 minutes. Generally, they require a shorter decoction time, preferably 5 to10 minutes.
Additionally, some non-aromatic drugs, such as Gou Teng (Ramulus cum Uncis Uncariae), Da Huang (Radix et Rhizoma Rhei), and Fan Xie Ye (Folium Sennae), should also be decocted later. These drugs should be soaked before decoction.
Decocted with Wrapping
Some Chinese herbal medicines with strong viscosity, powdery texture, fuzzy surface, or prone to stick to the pot should be wrapped for decoction, such as Xuan Fu Hua (Flos Inulae), Xin Yi Hua (Flos Magnoliae), Che Qian Zi (Semen Plantaginis), Pu Huang (Cattail Pollen), Hua Shi (Talcum), and Zao Xin Tu (Stove earth).
They should be wrapped in gauze bags before decocting with other drugs. This prevents the decoction from becoming turbid, irritating the throat, causing coughing, settling at the bottom of the pot, or causing carbonization or caramelization during heating.
Separate Decoction
Generally, precious Chinese herbal medicines are decocted separately, such as Ren Shen (Radix et Rhizoma Ginseng), Lu Rong (Cornu Cervi Pantotrichum), Xi Yang Shen (Panacis Quinquefolii Radix), and Ling Yang Jiao (Cornu Antelopis). This minimizes the loss of drugs and better extracts the effective ingredients.
They should be decocted separately for 2~3 hours. The decoction can be taken separately or mixed with other decoctions for consumption.
Dissolution
Some gelatinous and highly soluble Chinese herbal medicines should be dissolved, such as E Jiao (Colla Corii Asini), Lu Jiao Jiao (Cervi cornus Colla), Ru Xiang (Frankincense), and honey.
These drugs can be heated and dissolved in water or yellow wine, then taken with the decocted liquid, or heated and dissolved in the decocted liquid containing other drugs for consumption. This prevents these drugs from sticking to the pot or adhering to other drugs during decoction.
Infused decoction
Some Chinese herbal medicines with ingredients that are soluble in water or easily degraded by prolonged decoction should be administered by infusing, such as Xi Hong Hua (Stigma Croci), Fan Xie Ye (Folium Sennae), and Pang Da Hai (Boat-fruited Scaphium Seed).
These drugs can be infused with a small amount of boiling water or hot decoction, covered, and smothered to reduce volatilization. After half an hour, remove the dregs and take the liquid.
Direct Administration
Generally, Chinese herbal medicines ground into powder should be taken directly, such as She Xiang (Moschus), Niu Huang (Calculus Bovis), Zhen Zhu (Pearl), Hu Po (Succinum, Amber), Ling Yang Jiao (Cornu Antelopis), and Zhu Sha (Cinnabaris). They can be taken with warm water or decoction.
Decoction Substitution for Water
This refers to using the decoction of a certain drug instead of water for decoction. For example, Zao Xin Tu (Stove earth) contains a lot of sediment, and decocting it may cause the decoction to become turbid and difficult to take. Generally, it can be decocted first, and then the clear liquid on the top can be used instead of water to decoct other drugs.
In addition, some drugs with large volume, light weight, and strong water absorption, such as Yu Mi Xu (Corn Silk), Xia Ku Cao (Spica Prunellae), Si Gua Luo (Retinervus Luffae Fructus), and Jin Qian Cao (Herba Lysimachiae), can also be used with this method.