Yu Ping Feng: Boosting Qi and Securing the Exterior

Yu Ping Feng San (Jade Windscreen Powder) is the representative TCM formula for boosting qi and securing the exterior. It comes from the Jiu Yuan Fang, recorded in the Yi Fang Lei Ju, and has been passed down to the present. The original formula is: Fang Feng (Saposhnikovia) one liang; Huang Qi (Astragalus, honey-fried) and Bai Zhu (Atractylodes), each two liang; together ground to a powder. Three qian is taken each time with one and a half cups of water, plus one Da Zao (Jujube), decocted to seven-tenths, strained, and taken after meals. The modern patent medicine Yu Ping Feng Granules can be dissolved in boiling water and is sold in most pharmacies.

This formula mainly treats exterior-deficiency spontaneous sweating, presenting with sweating and aversion to wind, a pale-white complexion, a pale tongue with thin coating, and a deficient floating pulse; it can also treat frequent colds caused by low immunity in weak people. The late Mr. Li Changda, an old TCM physician from Sichuan, commonly used Yu Ping Feng San as a root-supporting formula when treating tumor patients.

In Yu Ping Feng San, raw Huang Qi is a key TCM herb for boosting qi, greatly supplementing the qi of the Spleen and Lung and serving as the jun (emperor) herb; Bai Zhu boosts qi and fortifies the Spleen, assisting Huang Qi in securing the exterior and consolidating the defense; Fang Feng has the action of expelling wind evil and is an important TCM wind-expelling herb; in this formula it assists Huang Qi and Bai Zhu in securing the exterior, so that the formula achieves the effect of supporting the root without retaining the pathogen. Yu Ping Feng San also has a modified version in which Bai Zhu is replaced by Bai Shao (White Peony), suitable for those with yin-deficiency spontaneous sweating.

In TCM there is another representative formula for exterior-deficiency spontaneous sweating, Gui Zhi Tang (Cinnamon Twig Decoction). The Taiyang wind-stroke pattern treated by Gui Zhi Tang also presents with sweating and aversion to wind. So how does one distinguish Yu Ping Feng San and Gui Zhi Tang in practice?

Gui Zhi Tang treats the disharmony of the ying and wei caused by external wind-cold; Yu Ping Feng San mainly treats the insecure exterior of weak people with easy and profuse sweating. Some formula textbooks therefore hold that Gui Zhi Tang should also have fever, nasal snoring, and body pain; in fact this explanation is problematic. Many cases of spontaneous and profuse sweating due to insecure exterior do not necessarily have fever, nasal snoring, or body pain; such patients are solved by Gui Zhi Tang but not by Yu Ping Feng San.

I have treated some patients who were exactly like this: they sweated spontaneously and profusely year-round, sweating like rain with slight exertion or after a hot drink, some with a history of over ten years, yet without fever, nasal snoring, or body pain. During this time they had also taken Yu Ping Feng Granules without effect, but responded markedly to Gui Zhi Tang.

The indications of these two formulas are hard to distinguish. Gui Zhi Tang has a floating moderate pulse, while Yu Ping Feng San has a deficient floating pulse; in reality a deficient floating pulse and a floating moderate pulse are very similar and hard to tell apart—both are floating and forceless. So the pulse can hardly serve as the criterion for choosing between them. Both indications include sweating and aversion to wind. According to Professor Hu Xishu, after a normal person sweats they will all be a little averse to wind: for one thing, sweat carries away some body heat; for another, the sweat on the skin cools in the wind and brings discomfort. So sweating with aversion to wind is also a poor distinguishing criterion.

I believe the key distinguishing points are the patient's complexion and strength. Yu Ping Feng San is a tonifying formula; patients mostly have a pale complexion from qi deficiency and a weak, feeble body. Gui Zhi Tang patients, on the other hand, have an exterior contraction or its sequelae: they either accompany the exterior symptoms such as headache and nasal snoring, or have none of the above, with basically normal strength and no qi-deficiency weakness.

So Yu Ping Feng is suitable for chronic-disease patients; it raises their immunity. In addition, Yu Ping Feng San is one of the representative formulas for "great fever treated with sweet-warm herbs" (gan wen da chu da re): qi-deficiency fever with sweating and aversion to wind can be reduced with Yu Ping Feng San, especially in leukemia or lymphoma patients with qi deficiency, who when reducing fever should not simply use surface-releasing formulas but tonifying formulas—moderately adding wind-expelling herbs such as Fang Feng and Jing Jie while tonifying qi and blood works very well.

Some literature also says Yu Ping Feng San raises immunity in patients with chronic rhinitis and chronic lung disease and can prevent recurrence, so it can be used as a routine preventive against recurrence in such patients. Also, in my experience, both Yu Ping Feng San and Gui Zhi Tang work poorly for hyperhidrosis in menopausal women, so they are not suitable for that condition.