产吴兴者胜。直下抽根一二十条。类牛膝而短。一种味极苦涩。经冬不凋。名
石龙胆。类同而种别。（核）
根苦涩。大寒。气味俱浓。沉而降。阴也。足厥阴少阳经气分药。又入足少阴阳明经。
草龙胆是少阳枢药。少阳化气。属相火。用苦寒对待治之。（之颐）主肝胆邪热。下焦湿火
肿痛。疗骨间寒热。惊痫邪气。目中肿痛诸患。除胃中伏热。湿热黄胆。时气温热。热泻下
痢。治小儿壮热骨热。惊痫入心。时疾热黄。（诸本草）除下部风湿及湿热。（肝胆为风木之
脏。而藏血者。固易为湿热之病。）治脐下至足肿痛。并寒湿香港脚。下行之功与防己同。酒
浸则能上行外行。治眼中之病必用。如两目赤肿睛胀。瘀肉高起。痛不可忍。当以柴胡为主。
胆草为使。（洁古）同苦参牛胆。治谷疸。同生地。治湿热伤血分。侵入大肠。以致卒下血。
同白芍甘草茯神麦冬木通。主小儿惊痫入心。壮热骨热。时疾热黄。口疮。同苦参蛆虫灰青
黛
〔论〕百物之生。气在味先。寒者水之气。热者火之气。气寒味苦者。本下降之气而泄。
气热味苦者。即本上升之气而泄。然阳者其精奉于上。元气以升为补。不若阴寒。其精降于
下。合于味之苦者。乃为泄也。龙胆草气大寒。味甚苦。就水中大泄火热。故用以治肝胆火。
并湿中蓄热者。夫肝胆表里。为相火所寄。与手厥阴少阳。历遍三焦之间。下合于脾肾之阴
以病。则为湿热。上合于肺胃之阳以病。则为风热。种种见证。须明其为本病为合病而用之
。或主或辅。庶乎适宜。要之。此等苦寒。可以治后天气血之病。不可以治先天元阴元阳之
病。即治气血。亦治有余而为热之病。非治不足而为热之病也。人身相火。在包络三焦则为
先天。在肝胆即为后天。后天藉先天以生。先天藉后天以成。如后天气血诸病。累及先天。
有时须于胆草。（惟肝胆为后天相火。故每与中五之土相为用。相为病。义见胡黄连条下。）
如泄后天相火。反致有伤谷气。又岂得为肝之利益哉。故用者宜审。
缪氏云。大寒纯阴。能除实热。胃虚血少之人。不可轻视。亦弗空腹服。令人溺不禁。
以其太苦。下泄太甚也。
〔修治〕 铜刀刮去须土。锉细。甘草水浸一宿。晒干。虚人酒炒黑用。
产于吴兴的龙胆草品质最佳。其根茎笔直向下，抽生出二十多条须根。形状类似牛膝但较短。有一种味道极其苦涩，经过冬天也不凋谢，名叫石龙胆。外形相似但品种不同。（核）
根部味苦性涩，药性大寒，气味都非常浓厚，药势沉降，属于阴类药物。它是足厥阴肝经和足少阳胆经气分的药物，又进入足少阴肾经和足阳明胃经。
草龙胆是调节少阳枢机的药物。少阳化生之气，归属于相火，使用苦寒性质的药物来对抗治疗它。（之颐）主治肝胆的邪热，下焦湿热引起的肿痛，治疗骨节间的寒热往来、惊痫等邪气，以及眼睛肿痛等各种病患。清除胃中潜伏的热邪，湿热导致的黄疸，时行温病发热，热性腹泻和下痢。治疗小儿高热、骨蒸潮热，惊痫入心，时行疾病引起的热黄。清除下部的风湿及湿热。（因为肝胆是风木之脏，且主藏血，所以容易患湿热病。）治疗从脐下到足部的肿痛，以及寒湿引起的脚气（香港脚）。其下行功效与防己相同，若用酒浸泡则能上行并外达，治疗眼部疾病必须使用。例如双眼红肿、眼球胀痛、瘀肉高起、疼痛难忍，应当以柴胡为主药，龙胆草为使药。（洁古）与苦参、牛胆同用，治疗谷疸；与生地黄同用，治疗湿热损伤血分，侵入大肠，导致突然便血；与白芍、甘草、茯神、麦冬、木通同用，主治小儿惊痫入心、高热骨蒸、时行热黄、口疮。与苦参、蛆虫灰、青黛同用。
〔论〕万物的生长，气在味之前产生。寒是水的气，热是火的气。气寒味苦的药物，本质上是下降之气而具有泄降作用；气热味苦的药物，本质上是上升之气而具有泄降作用。然而，阳气将其精华奉养于上，元气以升发为补益，不如阴寒之气，将其精华降于下，结合味的苦性，才成为泄降。龙胆草气大寒，味极苦，能在体内大力泄降火热，所以用来治疗肝胆之火，以及湿中蓄积的热邪。肝胆互为表里，是相火寄居之处，与手厥阴心包经和手少阳三焦经，遍行于三焦之间，下合于脾肾之阴而发病，则为湿热；上合于肺胃之阳而发病，则为风热。各种见证表现，必须明确是其本经病变还是合病而使用此药。或作主药，或作辅药，才适宜。总之，这类苦寒药物，可以治疗后天气血的病变，不可以治疗先天元阴元阳的病变。即使治疗气血，也是治疗有余而表现为热的病变，不是治疗不足而表现为热的病变。人身相火，在心包络和三焦则属于先天，在肝胆则属于后天。后天依赖先天而生，先天依赖后天而成。如果后天气血诸病累及先天，有时需要在方中加入龙胆草。（只有肝胆是后天的相火，所以常与中央土脏相互为用，相互致病，含义见胡黄连条下。）如果泄降后天的相火，反而会导致损伤谷气（脾胃之气），这难道是肝脏的利益吗？所以使用者应当审慎。
缪氏说：龙胆草大寒纯阴，能清除实热。胃虚血少的人，不可轻视，也不要空腹服用，否则会令人小便失禁，因为其味太苦，下泄太过。
〔修治〕用铜刀刮去须根和泥土，锉细。用甘草水浸泡一夜，晒干。体虚之人用酒炒黑后使用。
The Gentianae Radix et Rhizoma produced in Wuxing is of superior quality. The rhizome grows straight down, producing twenty or more roots. It resembles Achyranthis Bidentatae Radix (Niuxi) but is shorter. One variety has an extremely bitter and astringent taste, does not wither through winter, and is named Shi Longdan (Stone Gentian). Although similar in appearance, it is a different species. (He)
The root is bitter and astringent, with a great cold nature. Its qi and flavor are both strong. It sinks and descends, belonging to the Yin category. It is a drug for the Qi level of the Foot Jueyin Liver Meridian and Foot Shaoyang Gallbladder Meridian, and also enters the Foot Shaoyin Kidney Meridian and Foot Yangming Stomach Meridian.
Cao Longdan (Grass Gentian) is a drug that regulates the pivot of Shaoyang. Shaoyang transforms Qi, which belongs to Ministerial Fire (Xianghuo), and is treated using bitter-cold substances to counteract it. (Zhiyi) It primarily treats evil heat in the Liver and Gallbladder, swelling and pain caused by damp-heat in the Lower Jiao, chills and fever between the bones, convulsions, epilepsy, and other evil pathogens, as well as various eye swellings and pains. It clears latent heat in the Stomach, jaundice due to damp-heat, febrile diseases from seasonal warm pathogens, hot diarrhea, and dysentery. It treats high fever and bone-steaming heat in children, convulsions and epilepsy affecting the Heart, and hot jaundice from epidemic febrile diseases. It removes wind-dampness and damp-heat in the lower body. (Since the Liver and Gallbladder are the organs of Wind-Wood and store Blood, they are prone to damp-heat diseases.) It treats swelling and pain from the umbilicus down to the feet, and gout (Hongxiangjiao) caused by cold-dampness. Its descending efficacy is similar to that of Stephaniae Tetrandrae Radix (Fangji); if soaked in wine, it can ascend and move outward. It must be used for treating eye diseases, such as redness and swelling of both eyes, distension of the eyeballs, protrusion of pterygium (Yu Rou), and unbearable pain. In such cases, Bupleuri Radix (Chaihu) should be the chief herb, and Gentianae Radix et Rhizoma (Dancao) the assistant herb. (Jiegu) Combined with Sophorae Flavescentis Radix (Kushen) and Niu Dan, it treats Gu Dan (Grain Jaundice). Combined with Rehmanniae Radix Recens (Shengdi), it treats damp-heat injuring the Blood level, invading the Large Intestine, leading to sudden hematochezia. Combined with Paeoniae Radix Alba (Baishao), Glycyrrhizae Radix et Rhizoma (Gancao), Poria (Fushen), Ophiopogonis Radix (Maidong), and Akebiae Caulis (Mutong), it treats pediatric convulsions and epilepsy affecting the Heart, high fever, bone-steaming heat, hot jaundice from epidemics, and mouth ulcers. Combined with Sophorae Flavescentis Radix (Kushen), ash of earthworms (Quchong Hui), and Indigo Naturalis (Qingdai)...
[Discussion] For all living things, Qi precedes Flavor. Cold is the Qi of Water; Heat is the Qi of Fire. Drugs with cold Qi and bitter Flavor possess a descending nature and have a purgative effect. Drugs with hot Qi and bitter Flavor possess an ascending nature but still have a purgative effect. However, Yang sends its essence upward, and Yuan Qi is tonified by ascending. This is inferior to Yin-Cold, whose essence descends downward. When combined with a bitter flavor, it becomes a purgative. Gentianae Radix et Rhizoma has a great cold Qi and very bitter flavor; it greatly purges fire and heat within the water element. Therefore, it is used to treat Liver and Gallbladder fire, as well as heat accumulated within dampness. The Liver and Gallbladder are interior-exterior partners and are the abodes of Ministerial Fire. They traverse the Sanjiao along with the Hand Jueyin Pericardium Meridian and Hand Shaoyang Sanjiao Meridian. When disease arises from their connection with the Yin of the Spleen and Kidney below, it manifests as damp-heat; when disease arises from their connection with the Yang of the Lung and Stomach above, it manifests as wind-heat. Various clinical manifestations require distinguishing whether the condition is a primary disease of these meridians or a combined disease before using this herb, either as a chief or assistant ingredient, to ensure appropriateness. In summary, such bitter-cold herbs can treat diseases of Postnatal Qi and Blood, but cannot treat diseases of Prenatal Primordial Yin and Primordial Yang. Even when treating Qi and Blood, they treat conditions of excess manifesting as heat, not conditions of deficiency manifesting as heat. The body's Ministerial Fire is considered Prenatal when located in the Pericardium and Sanjiao, but Postnatal when located in the Liver and Gallbladder. The Postnatal relies on the Prenatal for generation, and the Prenatal relies on the Postnatal for completion. If Postnatal Qi and Blood diseases affect the Prenatal, sometimes Gentianae Radix et Rhizoma must be included. (Only the Liver and Gallbladder represent the Postnatal Ministerial Fire, so they often interact pathologically and therapeutically with the Earth element of the Center; see the entry for Picrorhizae Rhizoma under Hu Huanglian.) If one purges the Postnatal Ministerial Fire excessively, it may damage Gu Qi (Grain Qi/Spleen-Stomach Qi), which would hardly benefit the Liver. Therefore, users must exercise caution.
Mr. Miao stated: Gentianae Radix et Rhizoma is great cold and purely Yin, capable of clearing excess heat. Individuals with deficient Stomach Qi and scant Blood should not underestimate it, nor should they take it on an empty stomach, as it may cause urinary incontinence due to its excessive bitterness and overly strong downward purging action.
[Processing] Scrape off the rootlets and soil with a copper knife, chop finely. Soak in Licorice water overnight, then dry in the sun. For deficient individuals, stir-fry with wine until blackened before use.