Ten Kinds of Dihuang Pills, Each with Different Effects
Liuwei Dihuang Wan is a patent medicine known to most ordinary Chinese people; everyone knows it is a good kidney-tonifying medicine. But in fact there are dozens of Dihuang-series patent medicines; the ten most commonly used share the same base formula, and by adding one or two herbs—or even just changing the proportions—the effects change.
The ancestral formula of the Dihuang series is Jinkui Shenqi Wan, a later name given because the formula comes from Zhang Zhongjing's "Jingui Yaolue." In the "Jingui Yaolue" itself it is called Shenqi Wan or Bawei Shenqi Wan.
The Shenqi Wan in the "Jingui Yaolue" is composed of 8 liang of Shengdi (dried rehmannia), 4 liang each of Shanyao and Shanzhuyu, 3 liang each of Zexie, Mudanpi and Fuling, and 1 liang each of Guizhi and Fuzi. The "Jingui Yaolue" records its use: "Grind the above eight herbs into powder, combine with refined honey into pills the size of Wu nuts, take fifteen pills with wine, increasing to twenty-five, twice a day." That is, make honey pills and take 15–25 with wine, twice daily.
The "Jingui Yaolue" mentions Shenqi Wan in four passages: 1. "Vacuity-tax lower back pain, with tension below the ribs and difficult urination, is governed by Bawei Shenqi Wan." (Chapter 6, On the Pulse and Treatment of Blood-Impediment and Vacuity-Tax Diseases); 2. "Shortness of breath with slight fluid retention should be drained through the urination; Linggui Zhugan Tang governs it, and Shenqi Wan also governs it." (Chapter 12, On Phlegm-Fluid, Cough and Dyspnea); 3. "In men, wasting-thirst with excessive urination—drinking one dou and urinating one dou—is governed by Shenqi Wan." (Chapter 13, On Wasting-Thirst, Small and Frequent Urination, and Lin); 4. "Question: A woman's illness, with eating and drinking as usual, but with vexing heat and inability to lie down, leaning on things to breathe—why? The Master says: This is called 'twisted bladder,' inability to urinate; because the bladder's duct is twisted, this disease arises. Just promote urination and it will resolve; preferably governed by Shenqi Wan." (Chapter 22, On Miscellaneous Gynecological Diseases).
From these four passages, Shenqi Wan mainly treats corresponding diseases by improving the patient's difficult or frequent urination. Later physicians have interpreted these four passages of the "Jingui Yaolue" in countless ways, many of which are over-interpretations, so I will not recount them.
Tōyama Yoshihiro held that people fall ill through poisoning of their own food, water and blood. Shenqi Wan is a famous formula for treating "water poisoning"; it resolves the various problems caused by retained water or frequent urination through diuresis. It can be used for cough and wheezing, diabetes, edema, effusions, profuse phlegm, lower back pain and many other diseases; the indication is frequent or difficult urination.
Water retained in the respiratory tract causes cough and wheezing; in the digestive tract it causes wasting-thirst; in the urinary system it causes frequent, urgent, painful and scanty urination; in the abdominal cavity, chest cavity, pericardium and pelvis it can cause ascites, pleural effusion, pericardial effusion and pelvic effusion. TCM does not care that these diseases have different names; as long as they are caused by internal retention of water, they can all be treated with water-draining formulas. So Shenqi Wan's indications are very broad.
I have used Shenqi Wan to treat many diseases fitting Tōyama's "own water-poisoning pattern," with recorded efficacy. I once treated a lung cancer patient's pleural effusion with long-term Shenqi Wan, controlling the effusion for over five years. Of course such cases are rare; pleural effusion is not so easy to control, and most patients are not so lucky.
The Jinkui Shenqi Wan now on the market is actually not the original Jinkui Shenqi Wan but is made according to the Jisheng Shenqi Wan formula. Jisheng Shenqi Wan is a later formula built on Jinkui Shenqi Wan plus two herbs, Niuxi and Cheqianzi; its diuretic effect is better than Jinkui Shenqi Wan. So when buying, check whether the package insert lists Niuxi and Cheqianzi: with these two ingredients it is Jisheng Shenqi Wan; without them it is Jinkui Shenqi Wan. Jisheng Shenqi Wan is also called Nioche Shenqi Wan in Japan (niu = Niuxi, che = Cheqianzi); Japan's Ministry of Health, Labour and Welfare has designated Jisheng Shenqi Wan as an adjuvant for cancer patients, mainly to solve various effusions.
Then why do we in China also call it Jisheng Shenqi Wan? Because this formula comes from "Jisheng Fang" by the Song-dynasty physician Yan Yonghe, who used Jisheng Shenqi Wan to treat kidney-deficiency edema. Because it added Niuxi and Cheqianzi, which have stronger diuretic action, it treats internal water retention better; later physicians therefore replaced Jinkui Shenqi Wan with it, and the Shenqi Wan of the "Jingui Yaolue" is now the less commonly used one.
The eight-herb Shenqi Wan still exists, but under another name, Guifu Dihuang Wan. Compared with the Shenqi Wan of the "Jingui Yaolue," today's Guifu Dihuang Wan has larger amounts of the warming Fuzi and Rougui. So although the eight herbs are the same, the different proportions lead to different efficacy. Guifu Dihuang Wan treats kidney-yang deficiency with aching and cold of the waist and knees, limb edema, difficult or excessive urination, phlegm-fluid cough and wheezing, and wasting-thirst. Compared with Jinkui Shenqi Wan, the Guifu Dihuang Wan pattern patient has the accompanying signs of cold hands and feet and aversion to cold.
Another famous Song-dynasty physician, Qian Yi, also modified the Shenqi Wan formula of the "Jingui Yaolue," removing the warming herbs Fuzi and Guizhi; Jinkui Shenqi Wan thus became the famous Liuwei Dihuang Wan, a famous kidney-yin-nourishing formula. Qian Yi was a pediatrician; in clinical practice he found that children taking the warming Fuzi and Guizhi had relatively obvious side effects, so he said children are a pure-yang body and should, when taking Shenqi Wan, have the acrid-hot Fuzi and Guizhi removed. Liuwei Dihuang Wan's indications therefore changed greatly; it is mainly used for kidney-yin depletion with dizziness and tinnitus, aching and weakness of the waist and knees, steaming-bone fever, night sweats and seminal emission, and wasting-thirst.
Not only do children have side effects from Fuzi and Guizhi; many adults also have obvious side effects. So once Liuwei Dihuang Wan appeared, it quickly became the best-known Dihuang pill. Many classical-formula enthusiasts criticize later physicians for modifying Zhang Zhongjing's original formula, but in fact these physicians, in clinical practice, respected facts and refined their predecessors' ancestral formulas; the modified formulas were more applicable to patients. We should affirm this progress rather than, out of antiquarianism, deny their contributions.
Zhu Danxi of the Jin-Yuan period was the founder of the yin-nourishing school; on Qian Yi's basis he further developed Liuwei Dihuang Wan into Zhibai Dihuang Wan. Zhibai Dihuang Wan adds Zhimu and Huangbai to Liuwei Dihuang Wan. Traditional TCM holds that it nourishes yin and clears heat; it can be used for yin deficiency with effulgent fire, steaming fever and night sweats, dry mouth and sore throat, tinnitus and seminal emission, and scanty dark urine.
Later, Duqi Wan appeared (Liuwei Dihuang Wan plus Wuweizi). Wuweizi stops cough and calms wheezing; with Wuweizi added, Duqi Wan focuses more on respiratory diseases. The ancients held that Duqi Wan benefits the source of the lung to generate kidney water, and tonifies the kidney to receive qi. It can treat cough and wheezing, hiccups, spermatorrhea and lower back pain caused by dual deficiency of lung and kidney. Today it is commonly used for diabetes, perimenopausal syndrome, chronic bronchitis, and chronic obstructive pulmonary disease.
Adding lung-moistening herbs such as Maidong and Baishao to Duqi Wan makes Maiwei Dihuang Wan. Maiwei Dihuang Wan is better at moistening the lung and stopping cough; TCM holds it suits patients with lung-kidney yin deficiency and upward flaming of deficient fire, clinically indicated when the patient has wasting-thirst, a red face with cold feet, and cough with much phlegm. This formula has good efficacy for chronic bronchitis and COPD.
TCM holds that deafness is also caused by kidney deficiency, so treating deafness also emphasizes tonifying the kidney and promoting urination. In Tōyama Yoshihiro's view, otitis media patients with damp ear, tinnitus and ear discharge also have internal water retention and need water-promoting formulas, so the Shenqi series is effective for deafness due to otitis media. Zuoci Erlong Wan is composed on this principle: built on Liuwei Dihuang Wan plus Zhuye Chaihu and Cishi, it has some effect on tinnitus and deafness.
Qiju Dihuang Wan adds the liver-clearing, eye-brightening Gouqi and Juhua to Liuwei Dihuang Wan; its effect leans toward clearing the liver and brightening the eyes, and it treats dim vision.
Mingmu Dihuang Wan further adds Cili and Shijueming to Qiju Dihuang Wan for even better eye-brightening. These two are common patent medicines for ophthalmic diseases and can treat glaucoma, dry eye and vitreous floaters.
There is also Guishao Dihuang Wan, built on Liuwei Dihuang Wan plus Danggui and Baishao; it is a gynecological medicine that treats women's blood-deficiency dizziness and metrorrhagia.
There are many more Dihuang variations; this article will not list them all. From the differences in composition approach, use and effects among the Dihuang series, we can see that TCM formula composition is exquisite: adding or removing one herb, or even changing the dosage of one herb, changes the action.
But distinguishing these formulas is not hard. As long as we have a deep understanding of the clinical effects of common Chinese herbs and a deeper grasp of the effects and therapeutic principles of certain classical famous formulas, we ourselves can also modify and adapt these formulas to suit various patients.