Fever, Fatigue, Chest Tightness and a Thick Dry Tongue Coating? Doctor Luo Dalun: Gan Lu Xiao Du Dan (Sweet Dew Detoxifying Elixir), the Principal Formula for Damp-Heat Epidemics
💬 Note from Doctor Luo: Dear friends, good morning, everyone. Today we continue with this epidemic, and I want to talk about the formulas that people found most effective during it. These are all classic formulas of Chinese medicine — during this epidemic, we in Chinese medicine found that they matched the current illness very well, so when certain patterns appeared, we turned to these classics.
Opening: one of the formulas Chinese medicine used most in this epidemic
Today’s formula is called Gan Lu Xiao Du Dan (Sweet Dew Detoxifying Elixir). Doctor Luo says this formula appeared very frequently during this epidemic.
💬 Note from Doctor Luo: So where does this formula come from? Its earliest appearance should be in a book called Yi Xiao Mi Chuan (Secret Transmission of Medical Efficacy), from the Qing dynasty. Whose name is on it? Doctor Ye Tianshi. When I mention Ye Tianshi, you all know — this is the physician of the Qing dynasty I have introduced before, an absolutely remarkable doctor.
Where does the formula come from? — Start with Doctor Ye Tianshi
Where did Doctor Ye Tianshi practice? In Suzhou. In today’s Suzhou there is a Duseng Bridge — when you visit the sights, the streets outside Duseng Bridge are all commercial, and the tourists all head for the shops. Right beside the bridge is Ye Family Lane — that was where Ye Tianshi lived, a large stretch of houses, and where he practiced medicine.
💬 Note from Doctor Luo: When Ye Tianshi was young, his family had been physicians for generations, but his father died early. After his father passed away, Ye Tianshi was entrusted to his father’s disciple to be taught medicine. But after teaching him for a while, the disciple said: no, I can’t teach this one — why? Because he is too clever. So he told him: go out and study under masters, you must seek out every renowned master, and your learning will grow all the greater.
So Ye Tianshi went out to study, and how many masters did he study under in a row? Seventeen renowned masters. He studied each one seriously, and every school and lineage fused in his mind into one — and he became a great master of his generation.
💬 Note from Doctor Luo: In his time, in the Qing dynasty, Ye Tianshi was essentially the number-one practitioner under heaven. What did the common people say? They said Ye Tianshi was the heavenly medical star descended to earth — you see how high that praise is, right?
Ye Tianshi’s achievements were truly enormous. Doctor Luo shares a personal story:
💬 Note from Doctor Luo: My own master’s thesis was a study of Ye Tianshi’s Lin Zheng Zhi Nan Yi An (Case Histories from the Clinical Guide). Study that book carefully and you will feel this man is far too good — every formula he writes, you can see several lines of thinking inside it, that feeling of every school fused into one. What was his greatest contribution? He founded the warm-disease school — he is its founding father. He wrote a book called Wen Re Lun (Treatise on Warm-Heat Diseases), and that book laid down the entire theoretical framework of warm-disease medicine. So this man was extraordinary.
Because his fame was so great, many medical books of the time, after they were written, worried about selling — so what did they do? They falsely attributed the authorship to Ye Tianshi. Pretend Ye Tianshi wrote it, and it would sell easily.
💬 Note from Doctor Luo: This book, Yi Xiao Mi Chuan, is signed Ye Tianshi, but some scholars believe the attribution is false. Is it false or not? Truth and falsehood are tangled here — it may well contain some genuine Ye Tianshi material, because the book is quite valuable, so we keep an open mind.
Another book, however, corroborates that this formula comes from Ye Tianshi. In the Qing dynasty there is a book called Xu Ming Yi Lei An (Sequel to the Classified Case Histories of Famous Physicians); in its plague section it records: during the Yongzheng reign, around Jiangsu and Suzhou, a plague was raging. The local governor, the official in charge, found it deeply worrying — the plague had broken out, and the local leadership was being criticized severely. So what did he do? He found Ye Tianshi and asked: can you produce a formula to save the people of this region? Ye Tianshi analyzed the situation and gave a formula — Gan Lu Xiao Du Dan.
Why did this formula later become so famous? Because afterward a great warm-disease physician appeared — Doctor Wang Mengying.
💬 Note from Doctor Luo: I have talked about Wang Mengying a great deal. He promoted this formula especially hard. He said: this is the principal formula for treating damp-heat epidemic disease — when the two evils of dampness and warmth combine to cause an epidemic, this should be the main formula; it is especially important. So Wang Mengying praised it greatly in his masterpiece Wen Re Jing Wei (Compendium of Warm-Heat Diseases), and from then on the formula spread throughout the market.
What does this formula treat? — Damp-heat epidemic, evil at the qi level
The indications of Gan Lu Xiao Du Dan are: damp-heat epidemic disease, with the evil at the qi level. What does that mean? First we have to clarify the two things: “damp” and “warm.”
First, dampness. Doctor Luo is from the northeast, where it is dry; but when he goes to Guangdong, within a few days he can’t stand it — his shirt seems glued to his body, sweating all the time. In places with heavy dampness, the external environment affects your body.
💬 Note from Doctor Luo: But dampness exists in many places — not everyone gets sick. The key is spleen qi deficiency. We usually say the spleen governs the transportation and transformation of water and dampness: if spleen qi is deficient, dampness easily enters the body from outside; and inside the body, internal dampness is also generated. So inside and outside combine, dampness easily becomes heavy, and it can cause illness. And if your qi movement is blocked, you are even more likely to be hit in such a place — you cannot control the changes in the external environment.
Second, warmth. “Warm” has two meanings: one is excessive heat in summer; the other is that winter, which should be bitterly cold, inexplicably turns warm — like a warm winter. Both are abnormal climate states. But who is most likely to fall ill in such conditions? People whose body fluids are insufficient.
💬 Note from Doctor Luo: For example, suppose you already have deficient fire internally, yin deficiency with blazing fire, drying up your fluids. Once the fluids are dried and insufficient, and then outside it is warm and you sweat heavily — friends, your body fluids become even more insufficient. What problems does fluid insufficiency cause? The circulation of qi and blood in your body goes wrong. Fluids are part of what makes up the qi of the meridians; they must circulate through the whole body. If your fluids are gone, it is like a riverbed that has lost its water — dried up in stretches. Now if you want to transport the defense troops, can you deliver them to their posts? No. So when fluids are insufficient, and outside it is hot and you sweat too much, and then you contract a warm disease — this is how warm disease comes about.
Every external contraction illness happens because the external environment changes and, at the same time, you have a pathological state inside — internal cause and external cause combine, and you fall ill.
Body fluids and dampness are two different things: a flood outside, but the tap at home runs dry
Some friends ask: you say the dampness is heavy, and the fluids are insufficient — so is there too much water in my body or too little? Doctor Luo says: body fluids and dampness are two different things, two different levels.
💬 Note from Doctor Luo: What are body fluids? They are the water you absorb — the water your body can use normally. What is dampness? It is water you cannot use — because your body has obstacles and problems, it cannot use it. So it is entirely possible for a person to be short of body fluids and heavy with dampness at the same time. Why does this pattern arise? Because your body’s transformation ability has failed — you lack the ability to turn outside water into water you can use. An analogy: outside, a flood is raging, a disaster is happening; but the tap in your own house has run dry — the pipes have a problem. The flood outside and the dry tap inside are unrelated — you cannot transform the flood into tap water. It is just like that state.
What does it look like when it strikes? — Fever and fatigue, chest tightness and bloating, a thick and dry tongue coating
When damp-heat epidemic disease breaks out, what does the patient show? Doctor Luo goes through it one by one: the dampness is heavy, and the heat signs are heavy too; the external evil has entered the body but is still at the qi level — in warm-disease medicine we speak of wei-qi-ying-xue (defense-qi-nutrient-blood); it has just reached the qi level, still on the surface, not yet penetrated deep into the organs, not yet caused severe deterioration of organ function — it has not touched the blood.
The specific symptoms:
- Fever: with evil qi and heat evil inside, the person runs a fever;
- Fatigue: especially tired and without strength — dampness traps the spleen, the spleen’s transportation and transformation fails, qi and blood do not circulate smoothly, and the person feels overwhelmingly sleepy and heavy;
- Chest tightness and abdominal bloating: the belly feels full and stuffy, not comfortable — dampness traps the spleen, and the spleen cannot function normally;
- Aching limbs: the four limbs ache; the external evil is inside and the meridians do not run smoothly;
- Sore throat: heat evil gathers in the throat;
- Dry mouth and thirst, with a thick yet dry tongue coating: heat evil is present and fluids are lacking. Note — someone will ask: isn’t the dampness heavy? Shouldn’t the coating be moist and greasy? No! A thick coating means heavy dampness, but the evil heat at the qi level has scorched the fluids dry, so many patients show a coating that is thick but dry — dry on the surface, without saliva, without fluids;
- Scanty dark urine: urine that is short in volume and deep in color — this is a signal of insufficient body fluids, and very likely a heat pattern;
- Loose stools, painful or turbid urination: with heavy dampness, the stool sometimes turns into diarrhea; urination is sometimes painful, sometimes turbid;
- Soggy rapid or slippery rapid pulse: the pulse beats fast, and both dampness and heat are severe.
💬 Note from Doctor Luo: The old textbooks say “dampness and heat equally heavy,” but in practice, in this formula the heat may run a bit stronger. Look at the composition of this formula — it shows you exactly how this illness is treated.
Formula breakdown (part 1): talc, oriental wormwood, baical skullcap — resolving the three burners from above and below
The formula first uses three herbs heavily: hua shi (talc), yin chen (oriental wormwood), and huang qin (baical skullcap).
💬 Note from Doctor Luo: Talc is a mineral. What does it do? It drains water and dampness, clears heat and resolves toxin, and especially resolves summer-heat. In summer, when summer-heat dampness is especially heavy and damp-heat is severe, talc can guide the heat evil out through the urine. So in this formula, the first herb used to clear heat is talc.
The second, yin chen — clears liver-gallbladder heat, also guiding it out through the urine, downward. The third, huang qin — clears heat of the upper burner, especially lung heat.
💬 Note from Doctor Luo: You see, the idea is to push the heat evil downward and expel it — give the evil a way out.
Huang qin is matched with lian qiao (forsythia) — everyone’s most-used heat-clearing, toxin-resolving herb; with she gan (blackberry lily), which soothes the throat; and with bo he (mint) — mint penetrates and disperses the evil, an acrid-cool exterior-releasing herb that pushes the evil upward and out. There is also chuan bei mu (Sichuan fritillaria) — also a cool herb, with a toxin-resolving effect and a slight cough-stopping, phlegm-transforming action.
💬 Note from Doctor Luo: So you see, the three burners are resolved from above and below: the evil heat of the upper burner, I scatter it from above; in the middle, yin chen; down below, talc pours the heat evil out through the urine. This is a formula centered on clearing heat — from the top to the middle to the bottom, it covers everything.
Formula breakdown (part 2): clematis stem, acorus, patchouli, eupatorium, white cardamom — aromatics to dissolve turbidity
Besides clearing heat, the formula must also drain dampness. In fact, the heat-clearing herbs already carry some dampness-draining function — talc itself drains this damp-heat outward. The other dampness-draining herbs include:
Mu tong (clematis stem) — clears heat, drains dampness, and eases painful urination. When heat and dampness bind inside, causing the qi transformation of the lower burner to fail, heat evil gathers there; mu tong clears heat, drains dampness, eases urination and guides the heat outward — it is especially effective for stinging pain on urination.
Then come the aromatic herbs. The first is shi chang pu (acorus):
💬 Note from Doctor Luo: Acorus drains dampness; once the dampness is gone, the orifices can open — the clear orifices become unobstructed, so it has an orifice-opening action; it can transform phlegm, regulate qi, invigorate blood and scatter wind. Acorus is a wondrous herb, one I use very often. Some people say acorus can make you smart — when treating conditions of clouded spirit, a brain that is dizzy and muddled, we use acorus. What is it actually doing? It is lifting the clear and descending the turbid: remove the dampness, and the orifices become clear and penetrating, and the person wakes up — this is called waking the spirit. Acorus also opens the orifices of the body — for example, in treating deafness and tinnitus we often add acorus: when dampness no longer veils the upper burner, the disharmony of the nine orifices is relieved. So acorus is a truly excellent herb.
What is acorus paired with in this formula? With huo xiang (patchouli), pei lan (eupatorium) and bai dou kou (white cardamom) — all aromatic qi-moving herbs. Doctor Luo tells a delightful difference between ancient and modern times:
💬 Note from Doctor Luo: Today, when you smell patchouli, people say: heavens, that’s a medicinal smell! But in ancient times this was called an aromatic herb. Today we all think only the scent of roses counts as fragrance, but in ancient times, herbs like patchouli, eupatorium, acorus, angelica (bai zhi), pubescent angelica (du huo) and sweet wormwood (qing hao) — these were all aromatic herbs, all fragrant.
Chinese medicine has a saying: aromatics dissolve turbidity — removing the damp-turbid qi. What is the reasoning?
💬 Note from Doctor Luo: Aromatic qi can move the spleen; it can rouse the spleen and stomach and get them turning again. Once the spleen and stomach are roused and turning, and the spleen governs the transportation and transformation of water-dampness, it gains the ability to transform this water-dampness. At the same time, aromatic qi can clear foulness and turbid evil qi — when the spleen and stomach are not roused, qi movement is blocked, and foul turbid qi gathers inside the body, including metabolic products, garbage, pathological products, and so on, that cannot be expelled; once the spleen and stomach are roused and qi and blood begin to recover, they can gradually push it all out. So aromatics can clear foul turbidity.
The key to treating this epidemic: dissolving the foul turbid qi
Acorus, patchouli, eupatorium and white cardamom — all of them wake the spleen; once the spleen is woken, they remove dampness and clear foul turbid qi, and make qi movement unobstructed. Doctor Luo says this is exactly one of the crucial points in treating this epidemic.
💬 Note from Doctor Luo: Now we see many patients whose tongue coatings are thick and greasy, or thick and dry. What does that mean? It means water-dampness and foul turbid qi have accumulated inside. What to do? You have to dissolve it, get qi and blood flowing smoothly again — and the tool for that is these aromatic qis. So look at this formula: clear the heat evil by clearing heat, drain the water-dampness by promoting urination, and add aromatic qi-moving herbs to open up qi movement and dissolve the foul turbid qi and dampness — this formula should be called a fairly complete formula.
How does it relate to San Ren Tang? — An enhanced version, made for plague
This formula resembles the San Ren Tang (Three-Seed Decoction) we discussed before. What is the difference?
💬 Note from Doctor Luo: It is heavier than San Ren Tang, and its heat-clearing power is stronger — it is like an enhanced version, and what is enhanced is the heat-clearing part. San Ren Tang can handle an ordinary external contraction; Gan Lu Xiao Du Dan was specifically created for — what? Treating plague. So this is a very complete formula.
During the treatment of this epidemic (then called Wuhan pneumonia), many Chinese medicine doctors remembered this formula:
💬 Note from Doctor Luo: They applied it with additions and subtractions, or applied its approach, and the results were very good. The formula can be adjusted — for example, add a little more heat-clearing, add a little more dampness-draining, adjust according to the situation, and the effect is excellent. I am introducing this formula to you for treating plague; and once you understand the formula, if you meet the same pattern — even if it is not plague, just an ordinary external contraction — this formula works as well.
The formula also exists as a patent medicine, called Gan Lu Xiao Du Wan (Sweet Dew Detoxifying Pills).
💬 Note from Doctor Luo: Gan Lu Xiao Du Wan is not very commonly used; I estimate that ordinary pharmacies may not carry it, but you can buy it online. So once we understand this formula, we can use the patent medicine with far more precision — that is the benefit. That is all for today; thank you for listening. Next we will introduce more ideas for preventing and treating this pneumonia, and I hope they will be of use to you.
Compiled from Doctor Luo Dalun’s lecture series (2020 COVID-19 prevention and treatment series). Gan Lu Xiao Du Dan first appears in Yi Xiao Mi Chuan (attributed to Doctor Ye Tianshi) and was championed by Doctor Wang Mengying in Wen Re Jing Wei as “the principal formula for damp-heat epidemics.”