White Peony or Red Peony in Gui Zhi Tang? The Real Difference Between Bai Shao and Chi Shao, and the Rules of Sweating Out a Cold — the Mysteries of the First Formula of the Shang Han Lun, Explained in Full by Doctor Luo
Patient search terms: what is the difference between white peony and red peony / sweating out a cold / how to take Gui Zhi Tang / sweating at the slightest movement / afraid of wind and cold / what to do when you catch a cold
Corresponding medical names: Taiyang wind strike · exterior deficiency pattern of cold damage · disharmony of ying and wei (nutritive and defensive qi) · Gui Zhi Tang pattern
Opening: the cliffhanger from the last case — resolved today
In the previous episode, we told the first case of Doctor Xu Shuwei’s Shang Han Jiu Shi Lun (Ninety Treatises on Cold Damage): in the spring of the gengxu year, Ma Hengdao fell ill with an exterior-contraction fever, and Doctor Xu Shuwei diagnosed a Gui Zhi Tang pattern. At that time enemy soldiers had broken through Zhenzhou, the drugstores had run out of peony root, and Doctor Xu Shuwei personally went out to the gardens to gather the herb himself. When someone remarked that Gui Zhi Tang ought to use white peony, he answered, “This is exactly what should be used” — he used red peony. In the last episode, we said that to understand this, you first have to understand what Gui Zhi Tang actually treats. Now that the formula’s meaning has been explained thoroughly, the riddle is ready to be unlocked.
💬 Note from Doctor Luo: Doctor Xu Shuwei’s whole article was written to settle exactly this question — in Gui Zhi Tang, should the peony be white or red? In Zhang Zhongjing’s time, he simply wrote “shao yao” on his prescriptions, without distinguishing white from red. So how did the split happen later? And why did Doctor Xu Shuwei argue for red peony? Today we will tell the story of white peony and red peony from beginning to end. Remember, Gui Zhi Tang is the first formula of the Shang Han Lun, honored as the “crown of all formulas” — on the surface it is just a few herbs, plus ginger and jujubes, yet its meaning runs very deep.
Zhang Zhongjing wrote only the two characters “shao yao” — the white/red split began in the Northern and Southern Dynasties
Let us first trace the history. In Zhang Zhongjing’s era, peony was not divided into white and red; a prescription simply said “shao yao.” Only in the Northern and Southern Dynasties did the distinction between white peony and red peony appear, in the writings of Tao Hongjing.
💬 Note from Doctor Luo: Tao Hongjing said the best white peony grew around Mount Baishan, Mount Jiangshan and Mount Maoshan — roughly the Jiangnan region of today. Where is Maoshan? In Jiangsu — yes, the Maoshan of the famous Maoshan Daoist masters. And where is today’s best white peony produced? Hangzhou bai shao — white peony from the Hangzhou region of Zhejiang is the finest. Unfortunately, the area around Hangzhou is so wealthy that nobody bothers to grow medicinal herbs, so true Hangzhou white peony is now extremely rare. The surrounding regions produce plenty, though — for instance, white peony from Bozhou, Anhui is produced in very large quantities.
By the Tang dynasty, the division of labor between white and red peony was spelled out fairly clearly: white peony tonifies and restrains yin; red peony drains and unblocks. Later, in the Song dynasty, Doctor Xu Shuwei took this very question to the famous physicians of his day, and everyone found it confusing — to be honest, plenty of people still cannot tell white peony and red peony apart today.
How do you tell white peony from red peony? Three sayings, examined one by one
So what plants are white peony and red peony, exactly? The ancients disagreed, and roughly three sayings have come down to us:
💬 Note from Doctor Luo: The first saying comes from Li Shizhen and others: the one that opens white flowers is white peony, the one that opens red flowers is red peony. This is not actually reliable — the root we call bai shao can put out flowers of all colors, white or red. So sorting by flower color does not hold up. The second saying: cultivated peony is white peony, wild peony is red peony — indeed, some wild-harvested peony is used as chi shao today, and this view exists in Chinese medicine circles as well. And there is a third: back when Tao Hongjing said the south of the Yangtze produced white peony, where did red peony grow? Later research based on the old texts suggests that red peony may have come from wild plants in the northwestern highlands, at slightly higher altitudes.
There is a charming Doctor Zhang Xichun story connected to this:
💬 Note from Doctor Luo: Doctor Zhang Xichun held the same view. He said he had never seen red peony before — later, when he went to Shenyang in Manchuria to found the Lida Hospital of Chinese Medicine and got out into the mountains, he saw wild peony growing there. So that is what red peony really looks like! From then on he knew: the peony that grows wild in the mountains is chi shao — that is how it all fits together.
One tonifies, one unblocks: the real difference in action
Setting aside the legends and getting down to the materia medica, the difference between white and red peony is perfectly clear:
- Bai shao (white peony): sour and sweet, slightly cold. Its main job is to restrain yin — nourish the blood and regulate menstruation, calm the liver and stop pain, restrain yin and check sweating. Because it is sour and astringent, it can nourish liver blood and ease spasmodic pain.
- Chi shao (red peony): slightly cold. Its main job is to unblock — disperse stasis and stop pain, invigorate the blood, clear heat and cool the blood.
💬 Note from Doctor Luo: The tradition states it plainly: bai shao tonifies, chi shao drains. White peony collects; red peony opens. And here is an interesting point: in the earliest materia medica classic, the Shen Nong Ben Cao Jing (Divine Husbandman’s Classic of the Materia Medica), the action of shao yao is described mainly as unblocking — transforming stasis and so on. Read in that light, Zhang Zhongjing’s era probably used red peony — Doctor Xu Shuwei’s view is correct! It was only as later generations of physicians developed the materia medica further and subdivided shao yao into many more actions that they discovered white peony’s excellent ability to restrain yin and harmonize the nutritive level, so white peony became the more common choice. The processing differs too: chi shao is simply dried in the sun, while bai shao is boiled, sliced, and then dried. Same plant, one leaning toward tonification and one toward unblocking — when prescribing, you match the herb to the person.
Fever calls for red peony, no fever calls for white peony — Doctor Xu Shuwei’s fine judgment
So why did Doctor Xu Shuwei insist on red peony? The key lies in this particular patient’s presentation.
💬 Note from Doctor Luo: What is the first symptom listed in Ma Hengdao’s case? Spring fever. You see, he came down with a fever right at the start. What does a fever tell us? That this patient’s ying and wei are badly out of harmony and his qi and blood are blocked — the body wants to push the pathogen out but cannot, so it starts to heat up. What is needed then? Unblocking. That is why Doctor Xu Shuwei held that such a patient should take red peony — once the channels are opened and qi and blood flow freely, the effect is excellent. That is the fine judgment Doctor Xu Shuwei showed in choosing his herbs.
So when do you use white peony?
💬 Note from Doctor Luo: An ordinary person who has just been hit by wind-cold — the north wind blows, and they feel a little afraid of wind and cold, a runny nose, a slight spontaneous sweat, aching joints — in this situation there is usually no fever, and you simply need to harmonize ying and wei, so white peony is enough; white peony restrains yin and harmonizes the nutritive level. Honestly, there is no enormous difference between white and red peony — some physicians prescribe Gui Zhi Tang with red peony their whole lives and get equally good results. Why do the vast majority of doctors today use white peony? Because most people nowadays do not get the truly severe exterior-contraction illnesses — there is no fever, and white peony from the start is enough. When there is a fever, many doctors add gypsum and the like, but actually opening the channels with red peony works very well too. So my suggestion is: judge by whether there is a fever — in Doctor Xu Shuwei’s case the very first symptom was fever, a pronounced fever, so he used red peony; for a low fever, sweating at the slightest movement, a stuffy nose, afraid of wind and cold — white peony is fine.
The original preparation and drinking method: pound the herbs, and a bowl of hot porridge is the rule
After explaining white and red peony, Doctor Luo walks through the preparation and drinking method of Gui Zhi Tang in detail — these are the rules the Shang Han Lun’s first formula set for itself.
💬 Note from Doctor Luo: Zhang Zhongjing was extraordinarily meticulous. The herbs were to be pounded into pieces (fu ju). Think about it — this much medicine pounded and boiled. The original dose: three liang of cinnamon twig, which is about 45 grams in today’s terms — nearly 50 grams of gui zhi; three liang of peony, also nearly 50 grams; two liang of honey-fried licorice, nearly 30 grams; three liang of fresh ginger, several dozen grams by today’s measure; and twelve jujubes. Our versions today have all shrunk — I generally use 20 or 30 grams of gui zhi, either works. But Zhang Zhongjing used this huge amount, pounded it, and then took seven sheng of water and simmered it over a low flame down to three sheng — seven parts of water slowly cooked down to three, the dregs strained out, allowed to cool, then drink one sheng — that is, one third of the decoction. And after drinking it you must take one bowl of hot thin porridge — rice porridge or millet porridge, either is fine — to boost the medicine’s action, using the porridge to harmonize the spleen and stomach qi. Then cover up with a quilt or clothing: “warm and cover for a while, and it is best when a light, pervasive sweat appears over the whole body” — a mild sweat is ideal. Never let the sweat pour off like running water, or “the disease will certainly not leave.”
There is a misconception common among modern people that Doctor Luo wants to call out:
💬 Note from Doctor Luo: Some people say, the more freely the pathogen comes out the better — just sweat buckets and the evil qi will come out with it, right? No! When you sweat in torrents, yin fluids leak out through the exterior, your body’s fluids are depleted, and you can no longer defend against the pathogen. Sweating is not the goal; it is not for expelling the pathogen — a light sweat means ying and wei have already been harmonized and qi and blood are flowing smoothly. The body being slightly more active and open than usual is the best state for fighting off the enemy. So remember: never chase a drenching sweat — a drenching sweat damages your own yin, and the illness gets worse instead of better.
Zhang Zhongjing wrote down every step after taking the medicine:
💬 Note from Doctor Luo: What if the sweat comes? “If after one dose the sweat comes and the illness is cured, stop taking the remaining doses; you need not finish the packet.” The sweat has arrived and the disease is gone — no need to finish the rest. What if no sweat? “Take it again following the previous method” — drink another dose the same way, with porridge again. Still no sweat? “Hasten the intervals of the later doses, and let all three doses be taken within half a day” — finish all three doses within half a day. I have seen people who only sweat after several doses; some sweat on the first try, others need several, and may even add foot-soaking or moxa on the Fengfu GV16 point before the sweat comes — constitutions differ, and the depth of the pathogenic invasion differs too. For severe cases: “take through day and night, observing around the clock” — keep taking the decoction without stopping; “if the pattern is still present, make and take another dose; if no sweat comes, take up to two or three packets” — this “packet” (ji) is the same unit as the “packet” of herbs we prescribe today; two or three packets are fine. The sweat must come — the channels open, ying and wei harmonize, and only then is it right. There are also prohibitions: “avoid raw and cold foods, sticky and slippery foods, meat and noodles, the five pungent vegetables, wine, cheese and foul-smelling things.” People today are not so strict about diet when taking Chinese medicine, but greasy and spicy food — control it as much as you can, because this formula works by its qi and flavor to harmonize the organs inside.
The first law of sweating: never sweat on an empty stomach
Hidden in this passage are three laws of inducing sweat that Doctor Luo says everyone who takes Chinese medicine should know. The first: do not sweat on an empty stomach.
💬 Note from Doctor Luo: You see how he has you drink a bowl of porridge — many people take Gui Zhi Tang on an empty stomach without the porridge and simply cannot get a sweat out. Why? This is what we call activating the stomach qi. As soon as grain and porridge enter the spleen and stomach, the digestive system starts working — Gui Zhi Tang itself is a formula that regulates the spleen and stomach, so you ride on that momentum, switch on the spleen and stomach’s nutrient-transforming function, give a push to the whole system that distributes nutrients to the body, and only then can qi and blood get moving. That is why you must not try to sweat on an empty stomach. When I was a student, I once wanted to induce a sweat — foot-soaking, I thought. Winters in Manchuria are very cold, and I soaked my feet but could not produce a drop of sweat no matter what. Then I figured it out: I was hungry. With an empty stomach, the sweat simply will not come. I quickly got a bowl of rice, a bowl of porridge, drank it down — and the sweat poured out at once. Just like that! Stomach qi is the source of ying and wei qi. When the refined essences of food enter the stomach, the ying and wei of the spleen and stomach can begin to circulate.
The second law: never chase a drenching sweat — sweating is the result, not the goal
The second law: do not induce a big sweat. This is what Zhang Zhongjing tells us plainly in this passage, and it is a misconception that must be abandoned.
💬 Note from Doctor Luo: People always imagine that sweating carries the pathogen out with it — that is your imagination. Zhang Zhongjing said “do not let the sweat pour off in torrents; if the sweat pours off in torrents the disease will certainly not leave.” You want zhi zhi sweat — a light, fine, pervasive sweat. What does this mean? Sweating is only a result: a light sweat means the body’s qi and blood are flowing vigorously, ying and wei harmonized and running smoothly — that is the goal. Many people love to drench themselves in sweat at the first touch of a pathogen, and after the drenching sweat, the exterior deficiency may become even more pronounced, and they catch illnesses more easily afterward. Remember: no drenching sweats at this stage.
The third law: dosage is set by the person — a light sweat means the dose has arrived
The third law concerns dosage. The way Chinese medicine sets doses is a completely different philosophy from Western medicine.
💬 Note from Doctor Luo: A Western pill is fixed — half a tablet, one tablet, two tablets a day. But can Chinese medicine set doses that way? Should a man over 1.8 meters tall, big and heavy, and a small thin person take the same dose? That makes no sense. So the ancient Chinese were extremely clever — they set the dose according to your body’s response. You can brew a little extra, but what is your dose? The moment a light, pervasive sweat appears — that is your dose, the amount has arrived. No sweat means the amount has not arrived; keep drinking. People’s constitutions differ, their physical foundations differ, and the pathogens they meet differ — the four seasons change, the depth of invasion changes. Can everyone take the same dose? The ancients solved this by saying: I do not care about the number — your body’s response to the medicine at this moment tells me the dose has arrived. What was your dose this year may not be next year; summer may not be the same either. So your dose is adjusted at all times. The ancient method: take one dose, watch the response — a light sweat, you feel all over, ah, the whole body is sweating, good — that is your dose; no sweat, keep drinking, and the moment the sweat comes, that is your dose. You see how clever the ancients were.
Gui Zhi Tang is not just for colds: the foundation formula for harmonizing yin and yang
After these three laws, Doctor Luo returns to Gui Zhi Tang itself — it is not only for treating colds.
💬 Note from Doctor Luo: Gui Zhi Tang treats the exterior-deficiency exterior-contraction — ying and wei out of harmony and insufficient, the exterior deficient, sweating at the slightest movement. When this kind of exterior deficiency meets wind-cold invading from outside, if you drink Gui Zhi Tang promptly at the very first moment, it basically solves the problem in one go; it is rare to need repeated doses. That is why, later, whenever I see Huai shan yao powder (Huai yam powder), my mind goes straight to Gui Zhi Tang — how to regulate the spleen and stomach, support the upright qi, make the channels more open and the ying and wei run more smoothly, bring out a light sweat, and drive the pathogen away. This is the law Zhang Zhongjing taught us. Later masters like Doctor Zhang Xichun made additions and subtractions on this formula — all of it is fine. And this formula treats more than exterior-contraction illness: Xu Lingtai said it well — when treating exterior-contraction illness, Gui Zhi Tang harmonizes ying and wei; when treating internal-organ illness, Gui Zhi Tang harmonizes yin and yang. When yin and yang are out of harmony, adjust yin and yang. Why? Look at it: gui zhi (cinnamon twig) is warm, sheng jiang (ginger) is hot, shao yao is sour and astringent, restraining yin, da zao (jujube) nourishes the blood, and gan cao (licorice) harmonizes everything — this formula is a yin-yang balancing formula.
Finally, Doctor Luo leaves us with a teaser:
💬 Note from Doctor Luo: That is all for today. Tomorrow we will talk about how Gui Zhi Tang is used in daily life — through the case records of the famous masters. Once you have a general understanding of Gui Zhi Tang and know when it can be used in everyday life, won’t that be wonderful? Dear friends, see you tomorrow.
Compiled from Doctor Luo Dalun’s commentary on the case records of Doctor Xu Shuwei.