Fuzi (Aconite) is first recorded in the “Shennong’s Classic of Materia Medica” as a lower-grade herb, stating, “Fuzi, with a pungent and warm flavor, is indicated for wind-cold cough, warming the middle, treating traumatic injuries, masses, blood stasis, cold-dampness causing weakness and spasms, knee pain, and inability to walk.”“Bielu” adds, “It is sweet, very hot, and highly toxic, indicated for cold and weak feet, wind-cold in the lumbar region, cold pain in the heart and abdomen, cholera with cramps, and for strengthening the muscles and bones, and it can induce abortion, being the king of all herbs.” Fuzi is a pungent, sweet, and very hot herb that can circulate through the twelve meridians and expel cold. Both the “Shennong’s Classic” and “Bielu” describe its effects on cold pathogens or cold-dampness harming Yang, leading to weakened Yang Qi.Yu Tuan states: “Fuzi possesses a robust quality, with the ability to break through barriers and seize victory, capable of guiding Qi tonics through the twelve meridians to restore lost original Yang; guiding blood tonics into the blood to nourish insufficient true Yin; guiding dispersing herbs to open the pores to expel exterior wind-cold; and guiding warming herbs to the lower jiao to eliminate internal cold-dampness.” It is evident that Fuzi, when properly combined, can treat various deficiency-cold syndromes.Fuzi was widely used during the Han dynasty, with 33 formulas in classical texts utilizing Fuzi, along with 4 additional modified formulas that also include Fuzi. Zhang Zhongjing primarily utilized it for its ability to revive Yang, warm the middle, disperse cold, warm Yang, promote water metabolism, and alleviate pain.(1) Treatment of Shaoyin disease with Yang deficiency syndrome:1. Treatment of irritability syndrome.Fuzi combined with dried ginger forms the “Dried Ginger and Fuzi Decoction,” used to treat Shaoyin Yang Qi deficiency, characterized by irritability during the day and calmness at night, with a deep and weak pulse. Adding Poria, Ginseng, and Licorice results in the “Poria Four Reversal Decoction,” used for Shaoyin with both Yin and Yang deficiency, causing day and night irritability without peace. The former is a simple and direct formula for reviving Yang; the latter is a complex formula for reviving Yang and nourishing Yin. Both formulas use Fuzi with dried ginger to revive Yang, hence the ancient saying that “without dried ginger, Fuzi cannot generate heat.” Fuzi combined with Ginseng enhances the effects; Ginseng strengthens Fuzi’s ability to revive Yang and stabilize collapse, while Fuzi enhances Ginseng’s ability to tonify Qi and generate fluids. The later “Ginseng and Fuzi Decoction” is used for cases of blood and Qi collapse, rapidly restoring Yin and stabilizing Yang, representing the development of the “Poria Four Reversal Decoction.”2. Treatment of Shaoyin Yang collapse with reversal syndrome.The “Dried Ginger and Fuzi Decoction” with added Licorice forms the “Four Reversal Decoction,” used to treat Shaoyin Yang deficiency with reversal, hence the name. This is a representative formula used by Zhang Zhongjing to revive Yang and rescue from reversal. This formula indicates that Fuzi with Licorice can warm and open the blood vessels, accelerating blood circulation, allowing for rapid recovery from cold extremities. Additionally, this formula can also be used for symptoms such as vomiting, diarrhea, and sweating, indicating that Fuzi with Licorice can also restore the Yang of the spleen and kidneys.3. Treatment of Shaoyin with excessive Yin obstructing Yang syndrome.If internal Yin-cold is excessive and Yang Qi is weak, with virtual Yang being obstructed by Yin-cold, it forms an obstructed Yang syndrome. At this time, Fuzi must be used. Obstructed Yang syndrome can be categorized into external obstruction and upper obstruction. For external obstruction, the “Tongmai Four Reversal Decoction” is used, with internal symptoms of diarrhea with clear stools, cold extremities, and a pulse that is weak and nearly absent, indicating excessive Yin; external symptoms show no aversion to cold, indicating false heat. The “Tongmai Four Reversal Decoction” is essentially a stronger version of the “Four Reversal Decoction” with increased dried ginger and Fuzi, thus its power to revive Yang and disperse cold is even greater, “capable of greatly strengthening original Yang, controlling both internal and external, and inviting external heat to return internally” (as stated in the “Jinjian”). It is named “Tongmai Four Reversal Decoction” to distinguish it from the “Four Reversal Decoction.”For upper obstruction, also known as Dai Yang syndrome, “Baitong Decoction” is used. This decoction consists of the “Dried Ginger and Fuzi Decoction” with added scallions, using dried ginger and Fuzi to revive lost Yang, while scallions promote circulation up and down, suitable for full-body cold symptoms with a red face. If after taking “Baitong Decoction” there is a drug rejection, one can add human urine or pig bile, salty, cold, and bitter substances as counteracting agents, “to counteract the Yin-cold nature, guiding the spicy heat of ginger and Fuzi downwards, serving as a counteracting guide” (as stated by Qian Tianlai). This is the “Baitong Decoction with Pig Bile.”4. Treatment of Yang collapse with fluid thirst syndrome.In the course of cholera, due to vomiting and diarrhea, not only is Yang harmed, but Yin can also be easily harmed. In cases of Yang collapse with fluid thirst, Zhang Zhongjing often uses Fuzi.“Shanghan Lun” states: “Aversion to cold, pulse weak but recovering, diarrhea stops, indicating loss of blood.” The aversion to cold and weak pulse with returning diarrhea indicates that the spleen and kidney Yang is unable to stabilize. If the diarrhea stops but aversion to cold and weak pulse persists, it indicates that the stopping of diarrhea is not due to the recovery of Yang Qi, but rather the depletion of Yin fluids. The “Four Reversal Decoction with Ginseng” is used to treat this. The “Four Reversal Decoction” is primarily composed of Fuzi, which can revive Yang and rescue from reversal, adding Ginseng to tonify Qi and stabilize collapse, generating fluids and nourishing Yin. The combination of Fuzi and Ginseng enhances the power of stabilizing Yang and nourishing Yin.“Shanghan Lun” states: “If vomiting and diarrhea have stopped, sweating occurs with cold extremities, and the limbs are rigid and unable to relax, with a pulse that is weak and nearly absent, the “Tongmai Four Reversal Decoction with Pig Bile” is indicated.” This syndrome also belongs to Yang collapse with Yin exhaustion, but is more critical, showing signs of upper and lower obstruction, thus presenting as vomiting and diarrhea having stopped, sweating with cold extremities, and rigidity of the limbs. The formula heavily utilizes Fuzi as the main ingredient in the “Tongmai Four Reversal Decoction,” reviving Yang and rescuing from reversal; adding pig bile can serve as a counteracting agent and also nourish Yin.(2) Used for Bi syndrome:1. Treatment of chest Bi syndrome.There are two classical formulas using Fuzi to treat chest Bi syndrome.One is the “Wutou and Chishizhi Pill,”used for “chest pain radiating to the back, back pain radiating to the heart.” This syndrome is due to Yin-cold congealing, preventing Yang Qi from reaching. The “Wutou and Chishizhi Pill” combined with Fuzi, dried ginger, Sichuan pepper, and Wutou, a group of very pungent and hot herbs, expels cold and alleviates pain; to prevent excessive dispersal, it is also combined with Chishizhi to warm the interior and solidify. This formula is particularly effective for chest Bi syndrome due to Yin-cold congealing.The second is the “Yiyu and Fuzi Powder.” This is suitable for “chest Bi with urgency.” This chest Bi is caused by cold-dampness obstructing the meridians, generally accompanied by symptoms of meridian rigidity. The formula uses Yiyu to disperse Bi and eliminate dampness, while Fuzi can warm Yang and disperse cold, as dampness is a Yin pathogen that disperses when warmed; it can also assist Yiyu in alleviating rigidity, as the “Shennong’s Classic” states that Fuzi can treat “cold-dampness causing weakness and rigidity,” as cold tends to constrict, dispersing when warmed.2. Treatment of wind-cold-damp Bi syndrome.Wind-cold-damp Bi syndrome primarily manifests as pain in the muscles and joints. This syndrome is caused by the obstruction of the meridians by wind-cold-damp pathogens. There are five classical formulas using Fuzi to treat this condition: “Gui Zhi and Fuzi Decoction,” “Bai Zhu and Fuzi Decoction,” “Gan Cao and Fuzi Decoction,” “Fuzi Decoction,” and “Gui Zhi, Shao Yao, and Zhi Mu Decoction.”“Jinkui” states: “After 8 or 9 days of cold damage, if wind and dampness collide, the body aches and is restless, unable to turn or lie down, with no vomiting or thirst, and a pulse that is floating, weak, and rough, the “Gui Zhi and Fuzi Decoction” is indicated; if the stool is hard and urination is free, remove Gui Zhi and use Bai Zhu Decoction instead. The “Gui Zhi and Fuzi Decoction” is suitable for cases where wind-cold-dampness is lingering on the surface, and Yang Qi is already deficient. This formula heavily utilizes Gui Zhi to dispel wind while also promoting Yang and Qi, combined with Fuzi to warm the meridians and assist Yang. The combination is designed for cases of surface Yang deficiency with excessive wind-cold, with Gan Cao, ginger, and jujube harmonizing the Ying and Wei to treat surface deficiency. “If the stool is hard and urination is free,” it indicates that the dampness is on the surface, while the Yang Qi in the interior is already circulating. After treatment with the “Gui Zhi and Fuzi Decoction,” the wind pathogen has been expelled, but the cold-dampness remains. Therefore, Gui Zhi, which dispels wind and promotes Yang, is removed, and Bai Zhu is used with Fuzi to specifically control the water vapor in the skin, which is the “Bai Zhu and Fuzi Decoction.”“Jinkui” states: “If wind and dampness collide, causing joint pain, with tight and painful joints that cannot bend or stretch, and if near them the pain is severe, sweating occurs with shortness of breath, and urination is not smooth, with aversion to wind and reluctance to remove clothing, or slight swelling of the body, the “Gan Cao and Fuzi Decoction” is indicated.” The Gan Cao and Fuzi Decoction is for cases where wind-cold-dampness is present both on the surface and in the interior, thus showing joint pain, tightness, and inability to bend or stretch, along with symptoms of poor urination and swelling. Additionally, both surface and interior Yang Qi are deficient, thus also showing sweating, shortness of breath, aversion to wind, and reluctance to remove clothing. Therefore, Fuzi is used with Bai Zhu and Gui Zhi to act on both surface and interior, assisting Yang to dispel wind and transform dampness. Gan Cao is a famous herb that is particularly effective when combined with various pungent and hot herbs, as it can transform Yang and restore Yang Qi in both the surface and interior.Thus, Zhang Zhongjing created three famous formulas for wind-dampness. All three use Fuzi to warm Yang and disperse cold-dampness, but due to different combinations, they have slight variations. The “Gui Zhi and Fuzi Decoction” treats cases with excessive wind, the “Bai Zhu and Fuzi Decoction” treats cases with excessive dampness, and the “Gan Cao and Fuzi Decoction” treats cases with both wind and dampness; the “Gui Zhi and Fuzi Decoction” and “Bai Zhu and Fuzi Decoction” focus on surface Yang deficiency, while the “Gan Cao and Fuzi Decoction” addresses both surface and interior Yang deficiency.“Shanghan Lun” states: “In Shaoyin disease, if the body aches, hands and feet are cold, and joints are painful, with a deep pulse, the “Fuzi Decoction” is indicated.” Fuzi is used for Shaoyin Yang Qi deficiency, with cold-dampness lingering in the joints. Fuzi warms the meridians, disperses cold, and alleviates pain, combined with Ginseng to enhance the warming and cold-dispelling power, while Bai Zhu and Poria strengthen the spleen and eliminate dampness, preventing dampness from lingering. A strong and dry herb is counterbalanced with a single herb of Shao Yao, allowing for a balance of hardness and softness, capable of guiding Yang herbs into Yin to disperse cold, while also alleviating Bi and rigidity to relieve pain.Additionally, there is the “Gui Zhi, Shao Yao, and Zhi Mu Decoction,” suitable for cases of wind-dampness obstructing the joints. This formula also uses Fuzi to warm the meridians, disperse cold, and alleviate pain. However, due to the presence of wind-dampness obstructing the joints, causing pain and swelling, it is combined with Ma Huang and Gui Zhi to dispel wind and promote Yang, Bai Zhu and Fang Feng to eliminate wind and dampness; and due to prolonged illness, the pathogen can transform into heat, leading to Yin and blood deficiency, thus also adding Zhi Mu and Shao Yao to clear heat and nourish Yin, alleviating urgency and promoting Bi; ginger and licorice harmonize the stomach and restore proper Qi, with all herbs working together to dispel wind, eliminate warmth, warm the meridians, and promote Yin and clear heat.From this, it can be seen that in treating wind-cold-damp Bi syndrome, Zhang Zhongjing often uses Fuzi to warm Yang, disperse cold, and alleviate pain. This concretizes the description in the “Shennong’s Classic” that Fuzi is indicated for “cold, warmth, weakness, rigidity, and knee pain, leading to an inability to walk.” In cases of excessive wind with poor urination, it is often combined with Gui Zhi; when the surface dampness is more pronounced, it is also combined with Bai Zhu; if wind, cold, and dampness are both present, with poor urination and swelling, it is combined with Ginseng to greatly tonify original Yang; when Fuzi is combined with Zhi Mu and Shao Yao, it disperses cold without harming Yin, making it particularly suitable for cases of alternating cold and heat, and for those with both Yin and Yang deficiency.(3) Used for water retention disease:In cases of water retention disease with kidney Yang deficiency, Zhang Zhongjing often combines Fuzi to invigorate kidney Yang, warm Yang, promote water metabolism, or warm Yang and disperse water. There are five such formulas: Zhenwu Decoction, Guo Lou Qu Mai Pill, Ma Huang and Fuzi Decoction, and Gui Zhi with Shao Yao plus Ma Xin and Fuzi Decoction.“Shanghan Lun” states: “In Shaoyin disease, if it does not resolve after two or three days, and by the fourth or fifth day, if there is abdominal pain, poor urination, and heaviness and pain in the limbs, with diarrhea, this indicates water retention. The person may cough, have poor urination, diarrhea, or vomiting; the “Zhenwu Decoction” is indicated.” The Zhenwu Decoction is suitable for Shaoyin Yang deficiency, where fire does not generate earth, and the spleen and kidney Yang are deficient, leading to water retention. The formula uses Fuzi as the monarch to warm and invigorate kidney Yang, disperse cold, and transform water, combined with ginger to warm Yang and disperse water, with Poria to warm Yang and promote water metabolism, with Bai Zhu to warm Yang and strengthen the spleen, and with Shao Yao to balance hardness and softness, dispersing cold without harming Yin, with all herbs working together to achieve the effect of warming Yang and promoting water metabolism. This is particularly suitable for cases of kidney Yang deficiency with internal cold and water retention.Fuzi is also used to warm Yang and transform water in the Guo Lou Qu Mai Pill. This formula is also suitable for cases of poor urination with water retention. It uses Fuzi to warm Yang and transform Qi, combined with Qu Mai and Poria to promote water metabolism. Due to the presence of dryness and heat in this syndrome, it is also combined with Guo Lou root and yam to clear heat and generate fluids to alleviate thirst.For water retention disease that is more pronounced in the upper and outer regions, Zhang Zhongjing often employs warming and dispersing methods. In cases where the pulse is deep and also has kidney Yang deficiency, Zhang Zhongjing often adds Fuzi to warm and invigorate kidney Yang while dispersing cold and fluid. For example, the “Ma Huang and Fuzi Decoction,” “Jinkui” states: “Water disease, if the pulse is deep and weak, belongs to Shaoyin; if it is floating, it is wind; if there is no water and it is distended, it is Qi. For water, inducing sweating is sufficient. If the pulse is deep, the “Ma Huang and Fuzi Decoction” is indicated…” The “Ma Huang and Fuzi Decoction” consists of Ma Huang, Fuzi, and Licorice, with the three herbs working together to warm the meridians, induce sweating, and disperse water.If it is due to Yang deficiency and Yin condensation, with water retention not clearing, accumulating in the heart, presenting as “hardness under the heart, as large as a plate, with a swirling sensation, and water retention,” the “Gui Zhi with Shao Yao plus Ma Xin and Fuzi Decoction” can be used for treatment. This formula uses Gui Zhi and Ma Huang to induce sweating and disperse water; Fuzi and Xi Xin warm the meridians and assist Yang, penetrating both the surface and interior to disperse internal and external cold pathogens; Licorice, ginger, and jujube restore the middle Qi and harmonize the herbs, achieving the effect of warming the meridians, resolving the exterior, and dispersing water.All four formulas belong to cases of simple kidney Yang deficiency. For cases of both kidney Yin and Yang deficiency, presenting with poor urination and water retention, Zhang Zhongjing uses the “Eight Flavor Kidney Qi Pill.” This formula uses Fuzi and Gui Zhi added to tonify kidney essence and promote fluid metabolism. It is designed to “nourish Yin deficiency to generate Qi, assist Yang deficiency to transform water.”The characteristics of these five formulas are that Fuzi combined with Poria or Qu Mai can assist Yang and promote water metabolism; when combined with ginger, Ma Huang, or Gui Zhi, it can warm Yang and disperse water; when combined with Gan Di Huang, it can tonify both Yin and Yang, generating Yang and promoting water metabolism. This is something we should master.Additionally, the “Xiao Qing Long Decoction” states: “If there is choking, remove Ma Huang and add one piece of Fuzi, prepared.” This is due to excessive internal cold, obstructing the Qi pathway, and adding Fuzi with Ma Huang and Gui Zhi, warming Yang and transforming desire, which is also an example of using Fuzi to treat water retention disease.(4) Used for combined or concurrent diseases of Taiyang and Shaoyin:Fuzi is used in five formulas for concurrent diseases of Taiyang and Shaoyin. They are the “Ma Huang, Xi Xin, and Fuzi Decoction,” “Ma Huang, Fuzi, and Licorice Decoction,” “Gui Zhi with Fuzi Decoction,” “Gui Zhi without Shao Yao plus Fuzi Decoction,” and “Zhu Ye Decoction.”Among them, the “Ma Huang, Xi Xin, and Fuzi Decoction” and the “Ma Huang, Fuzi, and Licorice Decoction” are used for Taiyang and Shaoyin concurrent syndromes. “Shanghan Lun” states: “In Shaoyin disease, if it first presents with fever, and the pulse is deep, the “Ma Huang, Xi Xin, and Fuzi Decoction” is indicated.” It also states: “In Shaoyin disease, if it has lasted for two or three days, the “Ma Huang, Fuzi, and Licorice Decoction” can induce slight sweating, as there are no (interior) symptoms after two or three days, hence slight sweating is sufficient.”The “Ma Huang, Xi Xin, and Fuzi Decoction” uses Ma Huang and Xi Xin to expel the Taiyang pathogen, while Fuzi warms the interior of Shaoyin; the “Ma Huang, Fuzi, and Licorice Decoction” is for cases where the exterior pathogen is lighter, and the interior is more deficient, thus removing the dispersing Xi Xin and adding the Qi tonifying and harmonizing Licorice.Next, the “Gui Zhi with Fuzi Decoction” and the “Gui Zhi without Shao Yao plus Fuzi Decoction” are suitable for cases of mismanagement of Taiyang disease, where the Taiyang disease has not resolved, and the Yang Qi of Shaoyin is also deficient, forming a concurrent disease of Taiyang and Shaoyin. “Shanghan Lun” states: “In Taiyang disease, if sweating occurs, and it does not stop, the person has aversion to wind, poor urination, and the limbs are slightly rigid, making it difficult to bend or stretch, the “Gui Zhi with Fuzi Decoction” is indicated.” This is due to improper sweating in Taiyang disease, where the exterior symptoms have not resolved, but Yang has already been lost, leading to fluid loss. However, the fluid loss is due to Yang deficiency and the Wei Qi not being firm, thus the formula adds Fuzi to the Gui Zhi Decoction to warm the meridians and restore Yang, resolving the muscle and expelling wind. “Shanghan Lun” states: “In Taiyang disease, after purging, if the pulse is rapid and the chest is full, the “Gui Zhi without Shao Yao Decoction” is indicated; if there is slight aversion to cold, the “Gui Zhi without Shao Yao plus Fuzi Decoction” is indicated.” The “Gui Zhi without Shao Yao plus Fuzi Decoction” is indicated for cases where Taiyang disease has been mismanaged and purged, leading to damage to both chest Yang and kidney Yang, resulting in excessive Yin and Yang deficiency, thus Fuzi is added to warm the meridians and support Yang, removing Shao Yao’s Yin softness to prevent exacerbating the fullness in the chest.Lastly, there is the “Zhu Ye Decoction” for treating postpartum wind, presenting with fever, a flushed face, shortness of breath, and headache. This formula also contains Fuzi. The Zhu Ye Decoction is for cases of exterior heat combined with Shaoyin original Yang deficiency. The formula uses Fuzi combined with Ginseng to support Yang and tonify Qi, greatly replenishing original Yang; bamboo leaves and kudzu root clear heat; Gui Zhi, Fang Feng, and Platycodon promote sweating and resolve the exterior; ginger, jujube, and licorice harmonize the stomach Qi, also harmonizing the herbs. Together, they achieve the effect of supporting the righteous and expelling the evil.All five formulas use Fuzi to warm kidney Yang and stabilize the righteous, with the exterior being solid without sweating, combined with Ma Huang and Xi Xin; if the exterior is deficient with spontaneous sweating, it is combined with Gui Zhi and Shao Yao; if it is due to wind, it can be combined with bamboo leaves and kudzu root. Overall, this is a method of treating both the exterior and interior, with Fuzi working in conjunction with exterior-releasing herbs to assist Yang and resolve the exterior. This is also the true face of Fuzi as described in the “Shennong’s Classic” as being indicated for “wind-cold cough and reverse evil Qi.”(5) Used for insufficient Wei Yang syndromeClassical formulas using Fuzi to treat insufficient Wei Yang primarily include two formulas.One is the “Fuzi Xiexin Decoction,”indicated for “fullness under the heart, with aversion to cold and sweating.” Fullness under the heart is caused by stomach heat and Qi stagnation; aversion to cold and sweating indicates insufficient Wei Yang. Thus, the “Fuzi Xiexin Decoction” uses three Huang herbs to drain heat and clear phlegm, with Fuzi to support Yang and solidify the exterior.The second is the “Shao Yao, Gan Cao, and Fuzi Decoction.”“Shanghan Lun” states: “If sweating occurs and the disease does not resolve, with aversion to cold, it is due to deficiency. The “Shao Yao, Gan Cao, and Fuzi Decoction” is indicated.” Although sweating belongs to Yin fluids, it requires Yang Qi to promote it. After sweating, aversion to cold indicates that not only are Yin fluids damaged, but Wei Yang is also deficient, thus the “Shao Yao, Gan Cao, and Fuzi Decoction” is used, with Fuzi warming the meridians and supporting Yang to solidify the exterior.Additionally, Zhang Zhongjing’s famous wind-damp formulas, the “Gui Zhi with Fuzi Decoction” and the “Yue Bi Decoction” also state: “If there is aversion to wind, add Fuzi,” indicating that the use of Fuzi also has the intention of supporting Yang and solidifying the exterior.(6) Used for middle cold syndromeFuzi, as stated in the “Shennong’s Classic,” can “warm the middle,” thus Zhang Zhongjing uses it to treat middle cold syndrome.1. Treatment of middle cold with abdominal fullness and abscess syndrome.“Jinkui” states: “If there is cold Qi in the abdomen, with thunder-like pain, chest pulse fullness, and vomiting, the “Fuzi and Jingmi Decoction” is indicated.” This is due to spleen and stomach deficiency-cold, with cold-dampness rising, causing abdominal pain, chest pulse fullness, and vomiting. The formula uses Fuzi to warm the middle, disperse cold, and alleviate pain, with Ban Xia to transform dampness and descend the counterflow to stop vomiting, combined with Jingmi, Licorice, and Jujube to strengthen the spleen and harmonize the middle, alleviating urgency and stopping pain, achieving the effect of warming Yang, dispersing cold, descending counterflow, and harmonizing the middle.Additionally, the “Wumei Pill” syndrome of vomiting is due to stomach heat and spleen cold. The “Wumei Pill” also uses Fuzi, combined with dried ginger and Sichuan pepper to disperse cold from the spleen. Fuzi is also used for middle cold, but due to the presence of stomach heat disturbing, it is combined with Huang Lian, Huang Bai, and Wumei to clear stomach heat and calm the stomach.Furthermore, there are two formulas with modifications that also include Fuzi. The “Rizhong Decoction” states: “If there is fullness in the abdomen, remove Bai Zhu and add one piece of Fuzi”; the “Four Reversal Powder” states: “If there is abdominal pain, add one piece of Fuzi.” The former is for middle cold causing fullness, while the latter is for middle cold causing pain; in both formulas, the addition of Fuzi is for middle cold.2. Treatment of blood in the stool syndrome.“Jinkui” states: “If there is blood in the stool, first stool then blood, the “Huangtu Decoction” is indicated.” This blood in the stool is caused by middle cold and Yang deficiency, with the spleen unable to contain blood. The formula uses Fuzi combined with Bai Zhu, Huang Shi, to warm the middle, strengthen the spleen, and contain blood, with Di Huang and Ejiao nourishing Yin and blood to stop bleeding, and Licorice harmonizing the middle, with Huang Qin serving as a counteracting agent, achieving the effect of warming the middle and containing blood.3. Treatment of cold excess syndrome.“Jinkui” states: “If there is pain under the ribs, with fever, and the pulse is tight and wiry, this is cold, and warming herbs should be used, thus the “Da Huang and Fuzi Decoction” is indicated.” This is a syndrome of cold excess internally congealing. The formula uses Fuzi and Xi Xin to warm the meridians, disperse cold, and alleviate pain, combined with Da Huang to purge and promote bowel movements, with Fuzi and Da Huang working together to eliminate the cold nature while preserving the dispersing nature, achieving the effect of warming the middle and resolving cold accumulation.(7) Others:1. Treatment of intestinal pain.Zhang Zhongjing treats intestinal pain with pus and Yang Qi already deficient, using the “Yiyu, Fuzi, and Bai Jiang Powder.” This formula uses Yiyu and Bai Jiang to break down dysentery and expel pus; combined with Fuzi to invigorate Yang Qi, promote blood circulation, and disperse knots.2. Treatment of head wind syndrome.“Jinkui” states: “For head wind, use one piece of large Fuzi (prepared) and mix with salt in equal parts to create a powder, to be applied externally.” Although this formula is not specifically recorded in the “Jinkui” for its indications, it is also found in the “Qianjin” for head and facial wind, and in the “Wai Tai” for head wind and headache, thus it is known that this formula can be used for head wind and headache. Additionally, according to the “Shennong’s Classic,” Fuzi is indicated for “wind-cold,” thus this head wind and headache are likely caused by wind-cold invading the meridians of the head. Fuzi, with its pungent and sweet flavor and very hot nature, can disperse wind-cold from the meridians, while salt, with its slightly pungent flavor, can enter the skin to eliminate wind toxins. The combination of these two herbs works together to disperse wind-cold and alleviate pain. In modern times, Fuzi is ground into powder and mixed with vinegar for external application to treat sciatica, achieving therapeutic effects, which is a development of this formula.In summary, there are 33 formulas in classical texts that utilize Fuzi, with 4 additional formulas that include Fuzi, totaling 37 formulas. The Fuzi used in classical texts can be either raw or processed. Raw Fuzi is primarily used for Shaoyin Yang deficiency syndrome, with 8 formulas, while others use processed Fuzi. Fuzi is included in decoctions, pills, and powders in classical texts. The maximum dosage in decoctions is three pieces, with the minimum being one piece; in modern decoctions, the dosage generally ranges from 3 to 9 grams. Due to individual differences in constitution, some patients may use up to 60 to 120 grams, but this requires prolonged decoction. This is a special case and should not be regarded as a general situation, as it may lead to toxicity.In modern times, processed Fuzi is commonly used, as it retains its strong heart-reviving and stabilizing effects while significantly reducing toxicity. It is also recommended to decoct for 30 to 60 minutes to reduce toxicity, making it safer. The “Bielu” states that Fuzi can induce abortion, thus it should be avoided by pregnant women.Copyright Statement: This article was collected and organized by the Yueyahu Classical Formula Team. If there are any objections, please inform the editor, and we will delete it promptly.
