Chinese herbal medicine is one of the main treatment modalities in traditional Chinese medicine, carrying thousands of years of wisdom and culture and deeply rooted in people’s health management and daily life. However, many people often overlook the crucial step of decocting the herbs when receiving herbal therapy.

Whether the method of decoction is correct directly affects the extraction of active components from the herbs and the realization of their therapeutic effects. Correct decoction methods not only maximize the preservation of the herbs’ natural efficacy but also ensure patients receive the most optimal therapeutic outcomes. So, how should Chinese herbs be decocted correctly?

Prepare Before Decoction

First, select high-quality Chinese medicinal herbs. There are many types of Chinese medicinal materials, and even the same species can vary in quality; their quality often directly affects the efficacy of the decocted solution. It is generally recommended that patients obtain prescriptions and have them dispensed by professional physicians and pharmacists at licensed pharmacies or medical institutions. For patients who procure herbs themselves, when selecting materials they should carefully consider the source, variety, harvest time, and processing methods; choose standardized channels whenever possible to ensure quality. For some rare tonic herbs, such as ginseng or Cordyceps sinensis, in addition to verifying authenticity at purchase, attention should be paid to storage conditions to avoid adverse health effects from counterfeit or expired materials.

Second, clean the medicinal materials. Surface dust and impurities should be washed off with water first. If necessary, briefly soak in clean water before washing to ensure cleanliness. After cleaning, handle herbs without special decoction requirements appropriately to lay the groundwork for subsequent decoction.

Third, choose appropriate decoction utensils. It is generally recommended to use heat-resistant vessels such as ceramic pots or clay pots to better maintain stable temperature and prevent the herbal constituents from being damaged by sudden temperature changes. Iron, copper, and aluminum pots should not be used because these metals can affect efficacy. Whatever utensil is used, it should be cleaned and disinfected in advance to ensure the safety and effectiveness of the decocted herbal liquid.

Control the amount of water for decoction

After soaking, add an appropriate amount of clean water to the Chinese herbal medicine, with the water level 2–5 cm above the surface of the herbs, then proceed to decoct. The first decoction time should be kept to 0.5–1 hour, adjusted specifically according to the characteristics of the herbs.

When heating, control the fire: use strong heat to bring to a rapid boil for the first decoction, then switch to low heat to simmer slowly to fully release active constituents; if a second decoction is required, add water to the residue until the water level is about 2 cm above the herb surface, bring to a boil over strong heat, then simmer over low heat for 10–15 minutes. Finally, mix the two decoctions evenly and take in two doses.

Some single-herb preparations may have special annotations beside their names such as "decoct first," "add later," "wrap and decoct," "decoct separately," "melt," "take directly with water," etc.; the specific handling methods are as follows:

Pre-cook: Commonly used for substances such as magnetite, dragon bone, and oyster shell, which need to be boiled in advance for 20–30 minutes before being decocted together with other medicines;

Add later: Commonly used for substances such as Uncaria (Gou Teng), rhubarb (Da Huang), or peeled Amomum (sha ren without shell), which are added 5–10 minutes before the end of the first decoction and boiled together with the other medicines;

Bundle decoction: Commonly used for items such as plantain seed (Che Qian Zi) and Inula flower (Xuan Fu Hua); these herbs are placed in gauze and tied up, then put into the water and decocted together with the other medicines;

Separate decoction: Some precious herbs such as ginseng require separate decoction to prevent their extracted active constituents from being adsorbed by other herb residues;

Dissolution by heating: Gelatinous drugs such as Ejiao, when decocted, tend to adhere to other dregs and the pot bottom; this wastes the medicine and is prone to scorching. They should be separately dissolved in hot water and then mixed with the other decoction for administration;

Taken with water: Drugs that dissolve immediately in water, such as mirabilite, as well as juice-type materials like bamboo sap, should be taken with the prepared decoction or with boiled water.

These misconceptions can "dilute" therapeutic effects

Some people believe that the longer the decoction time and the higher the temperature, the better the efficacy. In fact, the solubility and stability of active components in Chinese medicines vary with temperature and duration. Excessively long or high-temperature decoction not only fails to comprehensively extract active components, but may also destroy heat-sensitive constituents, potentially reducing efficacy or producing toxic side effects.

Some patients believe that the more water added when decocting traditional Chinese medicine, the more active ingredients are extracted and the better the efficacy. In fact, failing to control the appropriate amount of water is also an important mistake in decocting; this can dilute the active components of the herbs and lead to reduced efficacy. After decoction, care must be taken to accurately separate the medicinal decoction from the residue, ensuring the concentration of the liquid taken is appropriate so as to achieve the intended health and therapeutic effects.