Erchen Wan: A Fine Formula for Draining Dampness and Resolving Phlegm
Erchen Tang comes from Taiping Huimin Heji Jufang, and the patent medicine Erchen Wan, based on this formula, is sold on the market. Erchen Wan is the representative Chinese medicine formula for damp-phlegm. It consists of six herbs: Fabanxia (processed Pinellia), Huajuhong (tangerine red peel), Fuling (Poria), Zhi Gancao (honey-fried licorice), Shengjiang (fresh ginger), and Wumei (smoked plum). Because Fabanxia and Huajuhong both work better the longer they are aged, the formula is named "Aged Two" (Erchen).
Traditional Chinese medicine holds that Erchen Tang (Wan) dries dampness, resolves phlegm, regulates qi, and harmonizes the middle. It treats damp-phlegm; whenever there is cough with abundant white sputum that is easy to expectorate, nausea and vomiting, chest and epigastric fullness, heavy limbs, or dizziness and palpitations, with a white slippery or greasy tongue coating and a slippery pulse, it may be used.
Today it is commonly used for chronic bronchitis, chronic gastritis, Meniere's disease, nervous vomiting, and chemotherapy-induced nausea and vomiting of the damp-phlegm type, with excellent effect. I have repeatedly used it for chemotherapy nausea and vomiting, with immediate effect. I have also used it for nausea from overeating raw/cold food or irregular eating in summer, with good results.
It can also serve as adjuvant therapy for reflux esophagitis, esophageal cancer, gastric cancer, and lung cancer. Used with the right pattern, it relieves the relevant symptoms and eases suffering. When treating cancer, anticancer drugs must be added.
In my experience, Erchen Wan works better than Erchen Tang, but Erchen Wan is unavailable in many places. When a patient needs it urgently, they buy the herbs locally and decoct Erchen Tang themselves. Adult dosage: Fabanxia 15 g, Juhong (if unavailable, Chenpi instead) 15 g, Fuling 10 g, Zhi Gancao 6 g, fresh ginger 7 slices, Wumei 1 piece. Children over ten may take the adult dose; under ten take half.
Chronic bronchitis, chronic obstructive pulmonary disease, bronchial asthma, and emphysema often present with damp-phlegm lodging in the lung; whenever sputum is abundant and easy to cough up, consider Erchen Wan or Tang with modifications.
The formula also treats vomiting well—whether from chronic gastritis, chemotherapy, morning sickness in pregnancy, membranous labyrinthine hydrops, nervous vomiting, or even motion sickness and seasickness. Mild reflux esophagitis and gastritis with nausea and reflux usually respond within 1–3 days.
Erchen Wan is also a common treatment for "phlegm nodules" from phlegm-dampness—i.e., various nodular diseases. It treats many polyps and tubercles, such as vocal-cord polyps, oral mucous gland cysts, gallbladder polyps, and scrofula (lymph node tuberculosis).
The formula rhyme summarizes Erchen Tang as "rectifying qi and harmonizing the middle, drying dampness and phlegm"—seven words that capture the key indication. The main pattern of Erchen Tang or Wan is qi stagnation with phlegm-damp obstructing the middle jiao—fullness and discomfort from the chest to the stomach, loose stools, a enlarged tongue, or a thick greasy coating or teeth marks. Once these main symptoms are recognized, regardless of the Western diagnosis, Erchen Tang or Wan may be used.