茎方作节。紫赤有细毛。叶似芍药。七月开白花。或茄色。花端丛刺。刺端有钩。八月
结黑子。宜三八月采根用。味苦咸。气微寒。苦下气。寒除热。咸润下而软坚。足少阴肾经
君药。主治补肾气。除阴中气分游火。清三焦气。散游风。疗热风头痛。明目。（以为少阴
君药。次之即肝。故目疾虚实皆用之。）祛喉舌浮热为病。育阴气。除心烦。治暴结热。
斑毒。通小便血滞。散瘤 瘰 。（散火之功。守真言结核是火病。）方书主消瘅中风虚劳伤
燥发热。着痹惊悸盗汗。口耳唇齿皮肤诸热为病。元参乃枢机之剂。管领诸气上下。整肃而
不浊。风药中多用之。治上焦空中氤氲之气。无根之火为圣药。又补肾中氤氲之气。降阴火
奔腾。同升麻甘草等分。水煎。治发斑咽痛。同鼠粘子半生半炒各两许。为末。新汲水服。
治急喉痹风。同地黄甘菊蒺藜杞子柴胡。能明目。同贝母连翘甘草薄荷栝蒌根夏枯草。治瘰
。同知母麦冬竹叶。治伤寒阳毒。汗下后热毒不散。心烦懊 不得眠。心神颠倒欲绝。同
黄连大黄等分。蜜丸。治三焦积热。同升麻大黄犀角。治胃热发斑。同贝母花粉芩连枳桔升
麻甘草。治上焦热痰盛而作渴。口舌肿痛。同升麻犀角黄芩甘草桔梗赤芍贯众。治心脾壅热
。舌上生疮。木舌舌肿。或连颊项肿痛。（以上实热。以下虚热。）入天王补心丹。除怔忡。
定惊悸。祛烦热。疗咽干。育养心神。入清热补气汤。治中气虚热。口舌如无皮状。或发热
作渴。入清热补血汤。治口舌生疮。体倦少食。日晡益甚。或目涩热痛。
〔论〕 元参色黑为水。润下本咸。味苦气寒。为足少阴的剂。与地黄功同益肾。而元
参所主者阴气也。地黄壮水以制火。元参则管领诸气。举浮游之火。或炎或聚者能清而散之。
之颐曰。已向乎阳。（为其味苦）未离于阴。（为其寒气）俨似少阴之枢象。殆具备少阴之体
用者。其补肾气。是补肾气方萌之机兆。非补肾脏欲藏之形质也。凡病本于气化热者。此能
致其至阴于气分。故热所结之气。不限上下。不分虚实。随其或主或辅。而皆可整肃。（凡
热遇至阴之气而即化）夫实为邪气实。除邪不能尽藉乎此。而以此味之阴气化气之并于邪者。
虚为正气虚。补正亦不能尽藉乎此。而以此味之阴气助气之歉于正者。元参之能事如是。用
之者宜量其所长也。缪氏谓元参禀水气而兼得春阳之和。此与风药中多用之义正合。（海藏）
虚而寒者切禁。凡血少目昏。停饮支满。腹痛泄泻。并不宜服。（仲淳）
〔修治〕 黑润者佳。酒洗。去尘土。酒拌蒸。切片晒干。极忌铜铁。入滋阴剂。须蒸
晒过。差减寒性。
茎呈方形，有节。颜色紫红，带有细毛。叶子形状像芍药叶。七月开出白花，也有茄子颜色的花。花顶端丛生着带钩的刺，刺的末端有钩。八月结出黑色的种子。适宜在三月或八月采集根部使用。味道苦、咸。气微寒。苦味能降气，寒性能清热，咸味能润下并软化坚硬之物。是足少阴肾经的主药。主要治疗补肾气，清除阴分中的游火，清三焦之气，疏散游风，治疗热风引起的头痛，明目。（因为作为少阴经的主药，其次关联肝脏，所以无论是虚证还是实证的目疾都可用它。）祛除喉舌浮热引起的疾病，滋养阴气，消除心烦，治疗突然发作的积热，斑毒，通利小便血滞，消散瘰疬。（散火的功效，正如朱丹溪所言，结核属于火病。）医书记载其主治消渴、中风、虚劳、伤燥发热、着痹、惊悸、盗汗，以及口、耳、唇、齿、皮肤等部位的热证。玄参是调节枢机的药物，统领上下诸气，整理肃清而不浑浊。风药中多使用它，治疗上焦空中氤氲之气，是无根之火的圣药。又能补肾中氤氲之气，降低阴火的奔腾。与升麻、甘草等量，水煎服，治疗发斑和咽痛。与牛蒡子半生半炒各一两左右，研为末，用新汲水送服，治疗急喉痹风。与地黄、甘菊、蒺藜、枸杞子、柴胡同用，能明目。与贝母、连翘、甘草、薄荷、栝楼根、夏枯草同用，治疗瘰疬。与知母、麦冬、竹叶同用，治疗伤寒阳毒，汗法或下法之后热毒未散，心烦懊恼不得安眠，心神颠倒欲绝。与黄连、大黄等量，蜜丸，治疗三焦积热。与升麻、大黄、犀角同用，治疗胃热发斑。与贝母、天花粉、黄芩、黄连、枳壳、桔梗、升麻、甘草同用，治疗上焦热痰盛而口渴，口舌肿痛。与升麻、犀角、黄芩、甘草、桔梗、赤芍、贯众同用，治疗心脾壅热，舌上生疮，木舌舌肿，或者连及脸颊颈部肿痛。（以上为实热，以下为虚热。）加入天王补心丹中，可除怔忡，定惊悸，祛烦热，疗咽干，养育心神。加入清热补气汤中，治疗中气虚热，口舌感觉像没有皮一样，或者发热口渴。加入清热补血汤中，治疗口舌生疮，身体疲倦，食欲不振，傍晚时分症状加重，或者眼睛干涩热痛。
〔论述〕 玄参色黑属水，本性润下且味咸，味苦气寒，是足少阴肾经的确切药剂。与地黄功效相同，都能益肾，但玄参所主的是阴气。地黄通过壮水来制约火，玄参则统领诸气，对于上浮游动的火，无论是炎症还是聚集，都能清解并疏散。张景岳说：玄参趋向于阳（因为其味苦），未离开阴（因为其性寒），俨然像少阴经的枢机形象，大概具备了少阴经的体用。它补肾气，是补肾气方萌发的机兆，而不是补充肾脏想要贮藏的形质。凡是病因基于气化热的病症，它能将至阴之气引入气分，所以热邪所结聚的气，不论在上在下，不分虚证实证，随着它是主症还是兼症，都可以被整理肃清。（凡是热遇到至阴之气就会化解）所谓实，是指邪气实，去除邪气不能完全依赖此药，但利用此药的阴气化气作用，可以辅助那些并入邪气的正气。所谓虚，是指正气虚，补益正气也不能完全依赖此药，但利用此药的阴气作用，可以助益那些亏欠的正气。玄参的能力就是这样。使用者应当衡量它的长处。缪希雍认为玄参禀受水气又兼得春阳的和气，这与在风药中多用的意义正相符合。（李东垣）阴虚而寒者严禁服用。凡是血少目昏、停饮支满、腹痛泄泻的人，都不宜服用。（陈实功）
〔炮制〕 以黑润者为佳。酒洗，去掉尘土。用酒拌蒸，切片晒干。极忌讳铜铁器。入滋阴剂时，必须经过蒸晒处理，以稍微减弱其寒性。
The stem is square and jointed. It is purple-red with fine hairs. The leaves resemble those of Paeonia lactiflora (Baishao). White flowers bloom in the seventh lunar month, or sometimes eggplant-colored. The flower tips have clustered prickles, and the ends of the prickles are hooked. Black seeds form in the eighth lunar month. The roots should be harvested in the third or eighth lunar months. The taste is bitter and salty. The nature is slightly cold. Bitterness directs Qi downward; cold clears heat; saltiness moistens downward and softens hardness. It is the sovereign herb of the Foot-Shaoyin Kidney Meridian. It mainly treats tonifying Kidney Qi, clearing wandering fire from the Yin aspect, clearing Sanjiao Qi, dispersing wandering wind, treating headache caused by wind-heat, and brightening the eyes. (As the sovereign herb of Shaoyin, it follows the Liver; thus, it is used for both deficiency and excess eye diseases.) It dispels floating heat causing disorders of the throat and tongue, nourishes Yin Qi, eliminates vexation, treats sudden accumulation of heat, macules/toxins, unblocks blood stasis in urination, and dissipates scrofula. (Its fire-dispersing efficacy aligns with Zhu Danxi's statement that nodules are fire diseases.) Medical texts state it treats xiao-dao (wasting-thirst), stroke, deficiency-labor, dryness-fever due to injury, fixed bi-syndrome, palpitations, night sweats, and various heat disorders of the mouth, ears, lips, teeth, and skin. Scrophulariae Radix (Xuanshen) is a pivot-regulating agent, managing Qi above and below, organizing and purifying without turbidity. It is frequently used in wind-dispelling formulas to treat misty Qi in the Upper Jiao and is the supreme medicine for rootless fire. It also nourishes the misty Qi in the Kidney and descends the surging Yin fire. Combined with equal parts Shengma Rhizoma (Shengma) and Glycyrrhizae Radix et Rhizoma (Gancao), decocted in water, it treats macules and sore throat. Combined with half raw and half stir-fried Niu Bang Zi (Arctii Fructus), each about one tael, powdered and taken with fresh well-water, it treats acute pharyngitis due to wind. Combined with Dihuang Radix (Dihuang), Ganju Ju Hua (Chrysanthemi Flos), Jili Fructus (Tribuli Fructus), Gouqizi (Lycii Fructus), and Chaihu Radix (Bupleuri Radix), it brightens the eyes. Combined with Beimu Bulbus (Fritillariae Bulbus), Lianqiao Fructus (Forsythiae Fructus), Gancao Radix et Rhizoma (Glycyrrhizae Radix et Rhizoma), Bohe Herba (Menthae Haplocalycis Herba), Gualougen Radix (Trichosanthis Radix), and Xiakucao Herba (Prunellae Spica), it treats scrofula. Combined with Zhimu Rhizoma (Anemarrhenae Rhizoma), Maidong Radix (Ophiopogonis Radix), and Zhuye Folium (Bambusae Folium), it treats Yang-toxin of Shanghan, where heat toxins remain unresolved after sweating or purgation, causing vexation, restlessness, insomnia, and extreme mental disturbance. Combined with equal parts Huanglian Rhizoma (Coptidis Rhizoma) and Dahuang Radix et Rhizoma (Rhei Radix et Rhizoma), made into honey pills, it treats accumulated heat in the Sanjiao. Combined with Shengma Rhizoma, Dahuang Radix et Rhizoma, and Xijiao Cornu Rinocerotis (Rhinoceoris Cornu), it treats macules due to Stomach heat. Combined with Beimu Bulbus, Huafen Radix (Trichosanthis Radix), Huangqin Radix (Scutellariae Radix), Huanglian Rhizoma, Zhike Fructus Aurantii (Aurantii Fructus Immaturus), Jiegeng Radix (Platycodonis Radix), Shengma Rhizoma, and Gancao Radix et Rhizoma, it treats excessive heat-phlegm in the Upper Jiao causing thirst, swelling, and pain of the mouth and tongue. Combined with Shengma Rhizoma, Xijiao Cornu Rinocerotis, Huangqin Radix, Gancao Radix et Rhizoma, Jiegeng Radix, Chishao Radix Paeoniae Rubra (Paeoniae Radix Rubra), and Guanzhong Rhizoma (Cyrtomii Rhizoma), it treats congestion-heat in Heart and Spleen, sores on the tongue, stiff/swollen tongue, or swelling/pain extending to cheeks and neck. (Above are excess heat; below are deficiency heat.) When added to Tianwang Buxin Wan (Emperor of Heaven's Tonic for the Heart Pill), it eliminates panic, calms palpitations, dispels vexation-heat, treats dry throat, and nourishes Heart Spirit. When added to Qingre Buqi Tang (Clear-Heat Tonify-Qi Decoction), it treats deficiency-heat of Middle Qi, sensation of skinlessness in mouth/tongue, or fever with thirst. When added to Qingre Buxue Tang (Clear-Heat Tonify-Blood Decoction), it treats sores in mouth/tongue, fatigue, poor appetite, worsening symptoms in the late afternoon, or dry/hot/painful eyes.
[Discussion] Scrophulariae Radix is black, corresponding to Water; its nature is descending and moistening, inherently salty; its taste is bitter and nature cold. It is the precise agent for the Foot-Shaoyin Kidney Meridian. Its merit in benefiting the Kidney is similar to Rehmanniae Radix (Dihuang), but Scrophulariae Radix governs Yin Qi. Rehmanniae Radix strengthens Water to control Fire, whereas Scrophulariae Radix manages all Qi, clearing and dispersing floating fire whether inflammatory or aggregated. Zhang Jingyue stated: It trends toward Yang (due to its bitter taste) yet remains within Yin (due to its cold nature), resembling the pivot image of Shaoyin. It likely embodies the substance and function of Shaoyin. Its tonification of Kidney Qi refers to the potential mechanism of Kidney Qi generation, not supplementing the physical substance the Kidney stores. For diseases rooted in Qi transformation turning hot, it brings Supreme Yin Qi to the Qi level. Thus, for Qi congealed by heat, regardless of location (upper/lower) or nature (excess/deficiency), it can organize and purify it according to whether it is primary or secondary. (When heat encounters Supreme Yin Qi, it transforms.) Excess refers to pathogenic excess; eliminating pathogens cannot rely solely on this herb, but its Yin Qi transforming Qi property assists Qi that has merged with pathogens. Deficiency refers to healthy Qi deficiency; tonifying healthy Qi cannot rely solely on this herb, but its Yin Qi property assists healthy Qi that is deficient. Such is the capability of Scrophulariae Radix. Users should measure its strengths. Miao Xiyong said Scrophulariae Radix inherits Water Qi and combines with the harmony of Spring Yang, which aligns with its frequent use in wind-dispelling formulas. (Li Dongyuan) It is strictly contraindicated for deficiency-cold. It is unsuitable for those with scant Blood and blurred vision, fluid retention with fullness, abdominal pain, or diarrhea. (Chen Shigong)
[Processing] Those that are black and moist are superior. Wash with wine to remove dust. Steam with wine, slice, and sun-dry. Copper and iron vessels are strictly forbidden. When used in Yin-nourishing prescriptions, it must be steamed and dried to slightly reduce its cold nature.