有补有泻，能表能里，可升可降
味甘。生用气平，补脾胃不足而泻心火（火急甚者，必以此缓之）。炙用气温，补三焦
元气而散表寒。入和剂则补益，入汗剂则解肌（解退肌表之热），入凉剂则泻邪热（白虎汤、
泻心汤之类），入峻剂则缓正气（姜、附加之，恐其僭上；硝、黄加之，恐其峻下，皆缓之
之意），入润剂则养阴血（炙甘草汤之类）。能协和诸药，使之不争。生肌止痛（土主肌肉，
甘能缓痛），通行十二经，解百药毒（凡解毒药，并须冷冻饮料，热则不效。小儿初生，拭去口
中恶血，绵渍汁令咂之，能解胎毒），故有国老之称。中满证忌之（甘令人满。亦有生用为
泻者，以其能引诸药至于满所。经云∶以甘补之，以甘泻之是已。故《别录》、甄权并云除
满，脾健运则满除也。仲景冶痞满，有甘草泻心汤。又甘草得茯苓，则不资满，而反泄满。
陶宏景，着《明医别录》，发明药性）。
大而结者良。补中炙用，泻火生用，达茎中（肾茎）用梢（梢止茎中痛，淋浊证用之）。
白术、苦参、干漆为使。恶远志。反大戟、芫花、甘遂、海藻。然亦有并用者（胡洽治痰癖，
十枣汤加甘草；东垣治结核，与海藻同用；丹溪治劳瘵，莲心饮与芫花同行，非妙达精微者
，不知此理。十枣汤，芫花、甘遂、大戟等分，枣十枚，仲景诒伤寒表已解，心下有水气、
喘咳之剂。时珍曰∶甘草外赤中黄，色兼坤离，味浓气薄，资全土德。协和群品，有元老之
功，普治百邪，得王道之化。赞帝力而人不知，参神功而己不与，可谓药中之良相也。昂按
∶甘草之功用如是。故仲景有甘草汤、甘草芍药汤、甘草茯苓汤、炙甘草汤，以及桂枝、麻
黄、葛根、青龙、理中、四逆、调胃、建中、柴胡、白虎等汤，无不重用甘草，赞助成功。
即如后人益气、补中、泻火、解毒诸剂，皆倚甘草为君，必须重用，方能见效，此古法也。
奈何时师每用甘草不过二三分而止，不知始自何人，相习成风，牢不可破，殊属可笑。附记
于此，以正其失）。
甘草具有补益和泻实的双重功效，既能作用于表证，也能作用于里证；药势既可上升，也可下降。
它的味道甘甜。生用性质平和，能补益脾胃的不足，同时清泻心火（如果心火亢盛严重，必须用此药来缓和它）。蜜炙后性质温热，能补益三焦元气并疏散体表寒邪。
在调和方剂中，它能起到补益作用；在发汗解表方剂中，它能解除肌表之热（即退去肌肉表面的热邪）；在清热凉血方剂中，它能泻除邪热（如白虎汤、泻心汤这类方剂）；在药性峻猛的方剂中，它能缓和正气（如在姜、附子中加入甘草，是担心药性上冲过头；在芒硝、大黄中加入甘草，是担心泻下过于猛烈，这都是为了缓和药性的用意）；在滋润方剂中，它能滋养阴血（如炙甘草汤这类方剂）。
它能协调各种药物，使它们之间不产生冲突。它能促进肌肉生长并止痛（脾主肌肉，甘味能缓解疼痛），通行于十二经脉，并能解百种药物的毒（凡是解毒的药，都必须用冷冻过的水送服，如果用热水则无效。小儿刚出生时，擦去口中的恶血，用绵絮蘸取甘草汁让婴儿吮吸，能解除胎毒），因此被称为“国老”。
对于中满（脘腹胀满）的病证要忌用甘草（因为甘味令人胀满。也有生用作为泻法的情况，因为它能引导其他药物到达胀满的部位。《内经》说：用甘味来补，用甘味来泻，就是这个道理。所以《名医别录》和李东垣都提到它能消除胀满，这是因为脾气健运则胀满自除。张仲景治疗痞满，有甘草泻心汤。另外，甘草遇到茯苓，不仅不会助长胀满，反而能泄除胀满。陶宏景著有《明医别录》，阐明了药性）。
质地大而坚实结实的甘草品质较好。用于补中气时宜蜜炙，用于泻火时宜生用，用于治疗阴茎部位疾病时用梢部（甘草梢能止阴茎疼痛，淋证、浊证时使用）。
以白术、苦参、干漆为佐使药。与远志相恶。与大戟、芫花、甘遂、海藻相反。然而也有配合使用的情况（胡洽治疗痰癖，在十枣汤中加入甘草；李东垣治疗结核，与海藻同用；朱丹溪治疗劳瘵，在莲心饮中与芫花同行，如果不是精妙通达药理的人，不知道这个道理。十枣汤由芫花、甘遂、大戟等分组成，加上十个大枣，是张仲景治疗伤寒表证已解，但心下有停水气，导致气喘咳嗽的方剂。李时珍说：甘草外红内黄，颜色兼具坤土和离火的特征，味道浓郁而气味轻薄，具备完整的土德。协调各类药材，有元老般的功劳，普遍治疗各种邪气，得到王道般的教化。辅助帝王之力而人不察觉，参与神功而自己不与争名，可以说是药中的良相啊。汪昂按语：甘草的功效如此。所以张仲景有甘草汤、甘草芍药汤、甘草茯苓汤、炙甘草汤，以及桂枝汤、麻黄汤、葛根汤、青龙汤、理中汤、四逆汤、调胃承气汤、建中汤、柴胡汤、白虎汤等方剂，无不重用甘草，赞助其成功。就像后人益气、补中、泻火、解毒的各种方剂，都以甘草为君药，必须重用才能见效，这是古法。奈何当时的医生每用甘草不过二三分就停止，不知道始自何人，相沿成习成为风气，牢不可破，实在可笑。特此记录于此，以纠正这种失误）。
Gancao (Licorice Root) possesses both tonifying and purgative properties; it can act on the exterior and the interior; its therapeutic action can ascend or descend.
Its taste is sweet. When used raw, its nature is neutral; it tonifies deficiencies of the Spleen and Stomach while draining Heart Fire (if Heart Fire is severely hyperactive, this herb must be used to moderate it). When honey-fried, its nature becomes warm; it tonifies the Yuan Qi of the San Jiao (Triple Burner) and disperses exterior Cold.
In harmonizing formulas, it provides tonification; in diaphoretic formulas, it releases the muscle layer (resolving heat from the muscular exterior); in cooling formulas, it drains pathogenic Heat (such as in Baihu Tang [White Tiger Decoction] and Xiexin Tang [Drain the Heart Decoction]); in harsh/strong formulas, it moderates the righteous Qi (when added to Ginger or Aconite, it prevents the herbs from rushing upward excessively; when added to Mirabilite or Rhubarb, it prevents excessive purgation; these are all measures to moderate the formula's intensity); in moistening formulas, it nourishes Yin and Blood (such as in Zhigancao Tang [Honey-Fried Licorice Decoction]).
It harmonizes various drugs, preventing them from conflicting with one another. It promotes tissue regeneration and relieves pain (the Spleen governs muscles, and the sweet flavor can alleviate pain), unblocks the Twelve Meridians, and detoxifies a hundred types of medicines (all detoxifying herbs should be administered with chilled water; if taken hot, they lose efficacy. For newborn infants, after wiping away evil blood from the mouth, soaking cotton in licorice juice for the infant to suckle can resolve fetal toxins). Therefore, it is known as "Guolao" (State Elder).
It is contraindicated in conditions of fullness in the middle jiao (sweet flavors cause distension. However, raw licorice can also be used as a purgative because it guides other herbs to the site of fullness. The Classic states: "Tonify with sweet, purge with sweet." Thus, *Bielu* [Supplementary Records of Famous Physicians] and Li Dongyuan both mention its ability to remove fullness; when the Spleen's transportation function is robust, fullness is resolved. Zhang Zhongjing treated epigastric fullness with Gancao Xiexin Tang [Licorice Decoction to Drain the Heart]. Furthermore, when Gancao interacts with Fuling [Poria], it does not exacerbate fullness but rather drains it. Tao Hongjing authored *Mingyi Bielu* [Supplementary Records of Famous Physicians], elucidating drug properties).
Those that are large and solid are of superior quality. Use honey-fried for tonifying the Middle Jiao; use raw for draining fire; use the tips (Shaobu) for treating the penis (the tips relieve penile pain and are used for stranguria and turbid urine).
It acts with Baizhu [Atractylodis Macrocephalae Rhizoma], Kushen [Sophorae Flavescentis Radix], and Ganqi [Drynariae Rhizoma] as assistants. It is inimical to Yuanzhi [Polygalae Radix]. It is chemically incompatible with Daji [Euphorbiae Pekinensis Radix], Yuanhua [Genkwa Flos], Gansui [Kansui Radix], and Haizao [Sargassum]. However, there are instances where they are used together (Hu Qia treated phlegm-stasis by adding Gancao to Shizao Tang [Ten Jujube Decoction]; Li Dongyuan treated tubercles by using it with Haizao; Zhu Danxi treated consumption diseases by using it with Yuanhua in Lianxin Yin [Lotus Plumule Decoction]; only those who deeply understand subtle principles know this rationale. Shizao Tang consists of equal parts Yuanhua, Gansui, and Daji, plus ten jujubes; it is a formula by Zhang Zhongjing for treating cases where the exterior syndrome of Shanghan [Cold Damage] has resolved, but fluid retention exists in the epigastrium causing wheezing and coughing. Li Shizhen stated: Gancao is red outside and yellow inside, combining the colors of Kun [Earth] and Li [Fire]; its taste is rich but aroma light, embodying the complete virtue of Earth. It harmonizes various ingredients, possessing the merit of a veteran statesman; it treats myriad pathogens, achieving the transformation of the Kingly Way. It assists imperial power without people noticing, participates in divine efficacy without claiming credit; it can be called the "Good Chancellor" among medicines.)
Wang Ang notes: The functions of Gancao are as described. Thus, Zhang Zhongjing utilized heavy doses of Gancao in Gancao Tang [Licorice Decoction], Gancao Shaoyao Tang [Licorice and Peony Decoction], Gancao Fuling Tang [Licorice and Poria Decoction], Zhigancao Tang [Honey-Fried Licorice Decoction], as well as Guizhi Tang [Cinnamon Twig Decoction], Mahuang Tang [Ephedra Decoction], Gegen Tang [Kudzu Decoction], Qinglong Tang [Azure Dragon Decoctions], Lizhong Tang [Regulate the Middle Decoction], Sini Tang [Reverse the Extremities Decoction], Xiaochengqi Tang [Minor Order the Chest Decoction - note: text says Diaowei Chengqi], Jianzhong Tang [Establish the Middle Decoction], Chaihu Tang [Bupleurum Decoction], and Baihu Tang [White Tiger Decoction], relying heavily on Gancao to assist in success. Similarly, in later formulas for boosting Qi, tonifying the Middle, draining fire, and detoxifying, Gancao is always the Sovereign herb and must be used in heavy doses to be effective; this is the ancient method. Alas, contemporary physicians often limit Gancao to two or three fen, starting from an unknown origin, becoming an unbreakable custom, which is truly laughable. I record this here to correct this error.