气温，味甘平。无毒。
手太阴经药。
《本草》云∶主补中益气，除热强阴。主头面游风，风头眼眩。下气，充五脏，长肌肉
，久服耳目聪明，轻身耐老，延年不饥。手太阴药，润皮毛燥，凉而能补，与二门冬、紫芝
为之使，恶甘遂。
东垣云∶仲景八味丸用干山药，以其凉而能补也。亦治皮肤干燥，以此物润之。
味甘、平。无毒。
入足太阴经，手阳明经。
《本草》云∶主补中益气，中风汗出，逐水，利小便，破积血，复血脉，乳妇产后余疾
。长发，可为沐药。久服肥健不老。
《液》云∶入足太阴、手阳明。汗多、冒热、便难，三者皆燥湿而亡津液，故曰脾约。
约者，约束之义，《内经》谓∶燥者润之，故仲景以麻仁润足太阴之燥及通肠也。
气微寒，味甘。无毒。
《本草》云∶主筋急拘挛，不可屈伸，风湿痹，下气。除筋骨邪气不仁，利肠胃，消
水肿，令人能食，久服，轻身益气。其根能下三虫。仲景治风湿燥痛，日晡所剧者，与麻黄
杏子薏苡仁汤。
气平，味甘，阳也。无毒。
入足厥阴经、太阴经、少阴经。
《象》云∶生用大泻热火，炙之则温，能补上焦、中焦、下焦元气，和诸药，相协而不
争，性缓，善解诸急，故名国老。去皮用。甘草梢子生用为君，去茎中痛，或加苦楝、酒煮
玄胡索为主，尤妙。
《心》云∶热药用之缓其热，寒药用之缓其寒。经曰∶甘以缓之。阳不足，补之以甘，
中满禁用。寒热皆用，调和药性，使不相悖，炙之散表寒，除邪热，去咽痛，除热，缓正气
，缓阴血，润肌。
《珍》云∶养血补胃，梢子去肾中之痛。胸中积热，非梢子不能除。
《本草》云∶主五脏六腑寒热邪气，坚筋骨，长肌肉，倍力。金疮 ，解毒，温中下气
。烦满短气，伤脏咳嗽。止渴，通经脉，利血气，解百药毒。为九土之精，安和七十二种石
，一千二百种草，故名国老。
《药性论》云∶君。忌猪肉。
《内经》曰∶脾欲缓，急食甘以缓之。甘以补脾，能缓之也，故汤液用此以建中。
又曰∶甘者令人中满。又曰∶中满者勿食甘。即知非中满药也。甘入脾，归其所喜攻也。
或问∶附子理中、调胃承气皆用甘草者，如何是调和之意？答曰∶附子理中用甘草，恐
其僭上也；调胃承气用甘草，恐其速下也。二药用之非和也，皆缓也。小柴胡有柴胡、黄芩
之寒，人参、半夏之温，其中用甘草者，则有调和之意。中不满而用甘，为之补，中满者用
甘，为之泄，此升降浮沉也。凤髓丹之甘，缓肾湿而生元气，亦甘补之意也。经云∶以甘补
之，以甘泻之，以甘缓之。《本草》谓∶安和七十二种石、一千二百种草，名为国老，虽非
君而为君所宗，所以能安和草、石而解诸毒也。于此可见调和之意。夫五味之用，苦直行而
泄，辛横行而散，酸束而收敛，咸止而软坚，甘上行而发，如何《本草》言下气？盖甘之味
，有升降浮沉，可上可下，可内可外，有和有缓，有补有泻，居中之道尽矣。入足厥阴、太
阴、少阴，能治肺痿之脓血而作吐剂，能消五发之疮疽。每用水三碗，慢火熬至半碗，去渣
服之。消疮与黄 同功，黄 亦能消诸肿毒疮疽。修治之法与甘草同。
《本草》又云∶术、干漆、苦参为之使。恶远志，反大戟、芫花、甘遂、海藻四物。
【山药】
药性温和，味甘、平。无毒。
归入手太阴肺经。
《本草》记载：主要功效为补益中气、益气力，清除虚热、滋养阴液。主治头面部游走性风邪，以及因风引起的头晕目眩。能降逆下气，充实五脏，促进肌肉生长。长期服用可使耳聪目明，身体轻盈，延缓衰老，延年益寿且不易感到饥饿。作为手太阴肺经的药物，它能滋润皮毛干燥，性质凉而兼具补益作用。与天门冬、麦门冬、紫芝配伍可增强疗效（为之使），畏忌甘遂。
李东垣说：张仲景在八味丸中使用干山药，是因为它性质凉而能补。也用于治疗皮肤干燥，利用此物的润燥之功来滋润肌肤。
【白术】
味甘、平。无毒。
归入足太阴脾经、手阳明大肠经。
《本草》记载：主要功效为补益中气、益气力，治疗中风导致的汗出异常，逐除水湿，通利小便，破除瘀血，恢复血脉通畅，治疗乳母产后余留的疾病。能促进头发生长，可作为洗头用药。长期服用可使身体丰满健壮，延缓衰老。
《液》（指《汤液本草》引用的其他文献或特定注本）记载：归入足太阴脾经、手阳明大肠经。汗出过多、中暑发热、大便困难，这三种情况都导致津液耗伤，因此称为“脾约”。约，即约束的意思，《内经》说：燥者润之，所以张仲景用麻子仁来润养足太阴脾经的燥邪并通便。
【薏苡仁】
药性微寒，味甘。无毒。
《本草》记载：主要功效为治疗筋脉拘急挛缩，关节不能屈伸，风湿痹痛，降逆下气。去除筋骨间的邪气所致的手足麻木不仁，通利肠胃，消除水肿，增进食欲。长期服用，可使身体轻盈，益气力。其根部能驱除三种寄生虫。张仲景治疗风湿疼痛，且在下午申时（日晡所）加重的病症，使用麻黄杏仁薏苡甘草汤。
【甘草】
药性平，味甘，属阳。无毒。
归入足厥阴肝经、足太阴脾经、足少阴肾经。
张元素（洁古）说：生用能大泻火热，炙用则性温，能补益上焦、中焦、下焦的元气，调和诸药，协同作用而不相冲突，药性缓和，善于解除各种急症，所以被称为“国老”。需去皮使用。甘草梢生用作为主药，可去除尿道疼痛；或者加入苦楝子、酒煮玄胡索为主药，效果尤为奇妙。
李杲（东垣）说：用于热性药物中可减缓其热性，用于寒性药物中可减缓其寒性。经书说：甘味能缓急。阳气不足，用甘味来补益，但中焦痞满者禁用。寒证热证皆可使用，调和药性，使药物不相违背。炙甘草可发散表寒，清除邪热，去除咽痛，清热，缓和正气，缓和阴血，滋润肌肤。
王好古（浩庵）说：养血补胃，甘草梢可去除肾脏部位的疼痛。胸中积热，非甘草梢不能清除。
《本草》记载：主治五脏六腑的寒热邪气，坚固筋骨，促进肌肉生长，增加力气。治疗金创（金属利器造成的创伤），解毒，温中降逆。治疗烦闷短气，损伤脏腑引起的咳嗽。止渴，通利经脉，调畅气血，解百种药物之毒。是九土中的精华，能安定和协调七十二种矿物药、一千二百种草药，所以被称为国老。
《药性论》记载：为君药。忌食猪肉。
《内经》说：脾喜缓，紧急时用甘味食物/药物来缓和它。甘味能补脾，能缓解脾的急迫，所以在汤液中常用它来建立中气。
又说：甘味使人中焦痞满。又说：中焦痞满者不要食用甘味。由此可知甘草并非专门治疗中满的药。甘味入脾，归于它所喜欢的部位进行攻治。
有人问：附子理中汤、调胃承气汤都用甘草，这如何体现调和之意？回答说：附子理中汤用甘草，是担心附子等药僭越上行；调胃承气汤用甘草，是担心大黄、芒硝等药泻下过快。这两方用甘草并非为了调和，而是为了缓急。小柴胡汤中有柴胡、黄芩的寒性，人参、半夏的温性，其中使用甘草，才是有调和之意。中焦不满而用甘味，是为了补益；中焦痞满而用甘味，是为了泄实，这涉及药物的升降浮沉。凤髓丹中的甘味，是缓和肾湿而生发元气，也是甘味补益的意思。经书说：用甘味补益，用甘味泻实，用甘味缓急。《本草》说：安定和协调七十二种矿物药、一千二百种草药，名为国老，虽然不作为君药，却是君药所尊崇的，所以能安定协调草石药物并解诸毒。从这里可以看出调和之意。五味的作用中，苦味直行而泄降，辛味横行而发散，酸味收敛束聚，咸味软坚止结，甘味上行而发散，为什么《本草》中说甘草能下气？大概甘味的药性，有升有降、有浮有沉，可上可下，可内可外，有和有缓，有补有泻，居中道的道理已经完备了。归入足厥阴、太阴、少阴经，能治疗肺痿吐脓血，作为催吐剂；能消除五种发疮疽。每次用水三碗，慢火熬至半碗，去渣服用。消疮的功效与黄芪相同，黄芪也能消除各种肿毒疮疽。炮制方法与甘草相同。
《本草》又说：白术、干漆、苦参为其佐使（为之使）。畏忌远志，反大戟、芫花、甘遂、海藻四物。
[Shanyao (Dioscoreae Rhizoma)]
The thermal nature is warm, the flavor is sweet and neutral. It is non-toxic.
It enters the Hand-Taiyin Lung Meridian.
Bencao states: Its main functions are tonifying the middle and boosting Qi, clearing heat, and strengthening Yin. It treats wandering wind on the head and face, and dizziness caused by wind. It directs Qi downward, replenishes the five Zang organs, promotes muscle growth, and with long-term use, improves hearing and vision, lightens the body, delays aging, extends life, and prevents hunger. As a drug for the Hand-Taiyin meridian, it moistens dry skin and hair; it is cooling yet tonifying. It acts as an assistant (Zhi Shi) when combined with Tianmendong (Asparagi Radix), Maidong (Ophiopogonis Radix), and Zizhi (Ganoderma). It is incompatible with Gansui (Kansui Radix).
Li Dongyuan said: Zhang Zhongjing used dried Shanyao in Bawei Wan (Eight-Ingredient Pill with Rehmannia) because it is cooling yet tonifying. It also treats dry skin by using its moisturizing properties.
[Bai Zhu (Atractylodis Macrocephalae Rhizoma)]
The flavor is sweet and neutral. It is non-toxic.
It enters the Foot-Taiyin Spleen Meridian and the Hand-Yangming Large Intestine Meridian.
Bencao states: Its main functions are tonifying the middle and boosting Qi, treating sweating due to stroke, expelling water, promoting urination, breaking up blood stasis, restoring blood vessels, and treating residual postpartum conditions in nursing mothers. It promotes hair growth and can be used as a shampooing agent. Long-term use makes the body robust and healthy, delaying aging.
Ye states: It enters the Foot-Taiyin Spleen and Hand-Yangming Large Intestine meridians. Excessive sweating, heatstroke, and difficult defecation all lead to fluid depletion, hence the term "Splee Constriction" (Pi Yue). "Yue" means constraint. The Neijing states: "Moisten what is dry." Therefore, Zhang Zhongjing used Mahuang Ren (Hemp Seed) to moisten the dryness of the Foot-Taiyin Spleen and unblock the intestines.
[Yi Yi Ren (Coicis Semen)]
The thermal nature is slightly cold, the flavor is sweet. It is non-toxic.
Bencao states: Its main functions are treating tendon spasms and contractures preventing flexion and extension, rheumatic bi-syndrome, and directing Qi downward. It eliminates pathogenic factors from bones and joints causing numbness, benefits the intestines and stomach, reduces edema, and stimulates appetite. With long-term use, it lightens the body and boosts Qi. Its root can expel three types of parasites. Zhang Zhongjing treated rheumatic pain that worsened at dusk (Ribu) using Mahuang Xingzi Yiyiren Tang (Ephedra, Apricot Kernel, and Coix Seed Decoction).
[Gan Cao (Glycyrrhizae Radix et Rhizoma)]
The thermal nature is neutral, the flavor is sweet, belonging to Yang. It is non-toxic.
It enters the Foot-Jueyin Liver Meridian, Foot-Taiyin Spleen Meridian, and Foot-Shaoyin Kidney Meridian.
Zhang Yuanjing said: Raw Gan Cao strongly clears fire and heat; roasted Gan Cao becomes warm and tonifies the Yuan Qi of the Upper, Middle, and Lower Jiao. It harmonizes various drugs, cooperating without conflict. Its nature is mild, and it is good at relieving various acute conditions, hence named "Guolao" (National Elder). Use the peeled root. Gan Cao Shao (the tip of the root), used raw as the chief ingredient, removes pain in the urethra; or combined with Kulian (Meliae Cortex) and Jiuzhu Xuyansuo (Vincae Rhizoma boiled in wine) as the chief ingredient, which is particularly effective.
Li Dongyuan said: When used with hot drugs, it moderates their heat; when used with cold drugs, it moderates their cold. The Classics state: "Sweetness moderates." For deficiency of Yang, tonify with sweetness, but avoid if there is fullness in the middle. It is used for both cold and heat patterns to harmonize drug properties and prevent incompatibility. Roasted Gan Cao disperses exterior cold, clears evil heat, relieves sore throat, clears heat, moderates Zheng Qi, moderates Yin Blood, and moistens the skin.
Wang Haogu said: It nourishes blood and tonifies the stomach. Gan Cao Shao removes pain in the kidneys. Accumulated heat in the chest cannot be cleared except by Gan Cao Shao.
Bencao states: It treats cold and heat pathogenic factors in the five Zang and six Fu organs, strengthens sinews and bones, promotes muscle growth, and increases strength. It treats metal wounds, detoxifies, warms the middle, and directs Qi downward. It treats irritability, distension, shortness of breath, and coughs due to organ damage. It stops thirst, unblocks meridians, benefits Qi and Blood, and resolves toxicity of hundred herbs. It is the essence of the nine soils, stabilizing and harmonizing seventy-two types of minerals and one thousand two hundred types of grasses, hence named Guolao.
Yaoxing Lun states: It serves as the Chief Drug. Avoid pork.
Neijing states: "The Spleen desires relaxation; urgently eat sweet things to relax it." Sweetness tonifies the Spleen and can relieve urgency, so it is used in decoctions to establish the Middle Jiao.
It also states: "Sweetness causes middle fullness." And: "Do not eat sweet things if you have middle fullness." Thus, it is known that Gan Cao is not specifically for treating fullness. Sweetness enters the Spleen and attacks where it is pleased.
Question: Both Fuzi Lizhong Tang and Tiaowei Chengqi Tang use Gan Cao. How does this reflect the meaning of harmonization?
Answer: In Fuzi Lizhong Tang, Gan Cao is used to prevent the rebellious ascent of other drugs; in Tiaowei Chengqi Tang, it is used to prevent rapid purgation. In these two formulas, Gan Cao is not used for harmonization but for moderation. In Xiaochaihu Tang, there is the cold of Chaihu and Huangqin, and the warmth of Renshen and Banxia; using Gan Cao here reflects true harmonization. If the middle is not full, using sweetness is for tonification; if the middle is full, using sweetness is for draining. This involves ascending, descending, floating, and sinking. The sweetness in Fengsui Dan moderates Kidney dampness to generate Yuan Qi, which is also the intent of sweet tonification. The Classics state: "Tonify with sweetness, drain with sweetness, moderate with sweetness." Bencao says: "Stabilize and harmonize seventy-two minerals and twelve hundred grasses," named Guolao. Although not the Chief Drug, it is revered by the Chief Drug, thus able to stabilize herbs and minerals and resolve various toxins. From this, we can see the meaning of harmonization. Regarding the use of the Five Flavors: Bitter goes straight down and drains; Pungent moves horizontally and disperses; Sour binds and converges; Salty stops and softens hardness; Sweet goes upward and disperses. How then does Bencao say it directs Qi downward? The nature of Sweetness has ascending/descending and floating/sinking qualities; it can go up or down, inside or outside; it has harmony and moderation, tonification and draining. The way of the center is complete. Entering the Foot-Jueyin, Taiyin, and Shaoyin meridians, it can treat pus and blood in Lung Wei (Flaccidity) as an emetic; it can eliminate sores and carbuncles of the five types. Boil three bowls of water slowly until half remains, remove dregs, and take. Its efficacy in eliminating sores is the same as Huangqi (Astragali Radix); Huangqi can also eliminate various swelling, toxic sores, and carbuncles. Its processing method is the same as Gan Cao.
Bencao further states: Baizhu, Ganzhi, and Kushen act as assistants. It is incompatible with Yuanzhi, and antagonistic to Daji, Yuanhua, Gansui, and Haizao.