Indications of Li Dongyuan's Shengyang Yiwei Decoction

Shengyang Yiwei Tang (“Yang-Raising Stomach-Benefiting Decoction”) comes from Neiwaishang Bianhuo Lun (Treatise on the Differentiation and Treatment of Internal and External Injury), and is also called Yiwei Tang. Its composition is: Huangqi (Astragalus) 2 liang (60g); Banxia (Pinellia, washed—this one herb is not used in large dosage when the pulse is choppy), Renshen (Ginseng, awns removed), and Zhigancao (honey-fried Glycyrrhiza), each 1 liang (30g); Duhuo (Angelica pubescens), Fangfeng (Saposhnikovia), Baishao (white Paeonia), and Qianghuo (Notopterygium), each 5 qian (15g); Chenpi (tangerine peel) 4 qian (12g); Fuling (Poria), Chaihu (Bupleurum), Zexie (Alisma), and Baizhu (Atractylodes), each 3 qian (9g); and Huanglian (Coptis) 1 qian (3g).

To use, crush the above herbs together; each time take 3–5 qian (9–15g), add one large cup of water (about 300 ml), 5 slices of Shengjiang (fresh ginger), and 2 Dazao (jujubes), and decoct to half a cup (about 150 ml), straining out the dregs. Take warm after meals, twice daily. Modern practice may also use one-third of the prescription amount as a decoction, directly decocting the prepared herbs into a soup, one dose daily, taken once in the morning and once in the evening.

Shengyang Yiwei Tang has the actions of boosting qi and raising yang, and clearing heat and eliminating dampness. It is indicated for spleen-stomach qi deficiency with lingering damp-heat, presenting as lassitude and desire to sleep, poor appetite with no taste, a heavy body with joint pain, a bitter mouth and dry tongue, abdominal glomus and distension, irregular bowel movements, frequent urination, aversion to cold with cold limbs, a depressed expression, and a haggard complexion. It is now often used to treat irritable bowel syndrome, depression, chronic bronchitis in the elderly, chronic renal proteinuria, and primary hypotension.

Traditional Chinese medicine holds that spleen-stomach qi deficiency prevents the body from properly transporting and transforming water-dampness, which in turn leads to retention of water-dampness; excessive dampness makes people prone to drowsiness, indigestion, and melancholy. Treatment should focus on transporting and transforming water-dampness, and must be approached on multiple fronts.

Shengyang Yiwei Tang on the one hand uses Huangqi, Renshen, Baizhu, and the like to fortify the spleen—when the spleen is vigorous, it readily transports water-dampness; on the other hand it uses Fuling and Zexie to promote diuresis and leach out dampness. At the same time it uses Chaihu, Fangfeng, Qianghuo, and Duhuo to expel wind and overcome dampness, and Huanglian to clear heat and transform dampness; Baishao is added both to restrain the dryness of the yang-raising herbs and to promote diuresis and expel dampness. Zhigancao harmonizes the various herbs, while Shengjiang, Chenpi, and Dazao strengthen the stomach. The combination of all these herbs comprehensively fortifies the spleen, clears heat, and resolves dampness; once dampness is gone, the spirit is clear and the body healthy, the appetite improves, and the mood is at ease.