禀仲春之气以生，兼得地之辛味春气生而升，故味苦平微寒无毒，为少阳经表药。
宜去芦锉片用。若入补中脾胃药，蜜酒拌炒干尤妙。
柴胡，泻肝火，去心下痰结热烦，散诸经血凝气聚，解肌表热，寒热往来，伤寒温
疟，痰实结胸，耳聋口苦，头眩目赤；在脏主血，在经主气，胎前产后，经脉不调，热
入血室，止偏头痛，胸胁刺痛，胆痹疼痛。湿痹拘挛，气药血药，并可加入；疮疽中用
之者，亦取其能散诸经血结气聚也。若病在太阳服之，犹引贼入门。若阳气下陷而有热
者，用之引清气，以顺阳道，而平少阳厥阴之邪热。若劳在肺肾者用之，益增伤阴耗气
之患。有色黄白而软大者，名银柴胡，乃治痨热骨蒸之要药也。
主治（痘疹合参） 解肌表热。凡初发热，而热毒太甚者，亦可用以托痘，痘后寒
症不宜用。专主肝、胆二经。是经为清净之腑，在半表半里，无出入之路，风邪所蓄。
不可汗吐下者，用此和解之。若欲升阳平肝，则又仗以所使成功也。
按∶柴胡乃少阳经半表半里之药，疟症有热时如火，形瘦骨立者，此名痨疟。热从
髓出，加以刚剂，气血愈亏矣，非柴胡莫能愈也。若病在太阳，用之太早，犹引贼入
内。病在阴经者，用之其重伤其表，世俗不明，表里混投，可以藏拙，然杀人不可胜数
矣。至于气虚者用之，不过些小以助参、 之力，非柴胡能退热也。若遇痨症便用，不
死安待？惟痨症在肝经者，别有银柴胡一种，色白而软，专理肝痨五疳羸热，亦非小
柴胡也。
柴胡禀受仲春时节的气候而生，兼有地之辛味。因春气主生发而上升，故其性味苦、平，微寒，无毒，是少阳经的表证用药。
适宜去除芦头后锉成薄片使用。如果用于补益中焦脾胃的药物中，用蜜酒拌炒至干尤其妙好。
柴胡能泻肝火，消除心下痰结引起的烦热，疏散各经血凝气聚之症，解除肌表之热，治疗寒热往来、伤寒温疟、痰实结胸、耳聋口苦、头晕目赤；在脏主要调理血分，在经主要调理气分，适用于胎前产后、经脉不调、热入血室、偏头痛、胸胁刺痛、胆痹疼痛等症状。作为气药或血药，均可加入方中；疮疽中使用它，也是取其能疏散各经血结气聚的作用。如果病在太阳经却服用柴胡，就如同引贼入室。如果是阳气下陷而产生内热的情况，使用柴胡可以升提清气，顺应阳气升发之道，从而平息少阳和厥阴的邪热。如果是肺肾劳损的情况使用柴胡，只会增加损伤阴液、耗伤元气的祸患。颜色黄白且质地软大的，称为银柴胡，它是治疗虚劳骨蒸发热的重要药物。
主治（结合痘疹分析）：解除肌表之热。凡是初期发热，且热毒过于严重的，也可以用柴胡来托毒出痘，但痘后出现寒症的不宜使用。专主肝、胆二经。这两经属于清净之腑，位于半表半里之间，没有出入的路径，风邪蓄积于此。不可用汗法、吐法、下法治疗的，用此药进行和解。如果想要升举阳气、平抑肝阳，则又要依靠柴胡来完成这一功效。
按语：柴胡是少阳经半表半里的药物。疟疾发作时热势如火，形体消瘦、骨骼显露的，这种病症名为痨疟。热邪从骨髓而出，如果加上刚烈的药剂，气血会更加亏损，此时非柴胡不能治愈。如果病在太阳经，过早使用柴胡，如同引贼进入体内。病在阴经者，使用柴胡会进一步重伤体表，世俗之人不明此理，表里病症混用投药，虽然可以掩饰自己的无知，但因此杀人的数量不可胜数。至于气虚的人使用柴胡，只是少量用以辅助人参、黄芪的力量，并非柴胡本身能退热。如果遇到虚劳病症就使用柴胡，不死还等什么？只有虚劳病症在肝经的，另有银柴胡一种，色白而质软，专门调理肝经虚劳及五种疳积引起的羸弱发热，这也不同于小柴胡汤。
Chai Hu (Bupleuri Radix) is born from the qi of mid-spring and possesses the pungent flavor of the earth. Since spring qi generates and ascends, its flavor is bitter, nature neutral, slightly cold, non-toxic, and it serves as a exterior-releasing herb for the Shaoyang channel.
It is suitable to remove the rhizome head and slice into pieces. If used in formulas tonifying the middle jiao and spleen/stomach, stir-frying with honey and wine until dry is particularly excellent.
Chai Hu clears liver fire, eliminates heat and irritability caused by phlegm accumulation below the heart, disperses blood stasis and qi stagnation in various channels, resolves exterior muscle heat, treats alternating chills and fever, shanghan (cold damage) and warm malaria, phlegm-solid chest fullness, deafness, bitter taste in the mouth, dizziness, and red eyes; within the zang organs, it primarily governs blood; within the channels, it primarily governs qi. It is indicated for conditions before and after childbirth, irregular menstruation, heat entering the blood chamber, hemi-cephalic headache, stabbing pain in the chest and hypochondrium, and gallbladder bi syndrome pain. As a qi-regulating or blood-activating herb, it can be added to prescriptions; when used for sores and carbuncles, it is utilized for its ability to disperse blood knots and qi aggregation in various channels. If administered when the disease is in the Taiyang channel, it is like inviting a thief into the house. In cases where yang qi has sunk and generated heat, using Chai Hu lifts clear yang, facilitates the smooth flow of yang, and pacifies pathogenic heat in the Shaoyang and Jueyin channels. However, if used for consumptive diseases involving the lungs and kidneys, it will only exacerbate the damage to yin and depletion of qi. Those that are yellowish-white and soft/large in texture are named Yin Chai Hu (Stellariae Radix), which is a key herb for treating consumptive fever and bone-steaming sensations.
Main Indications (Integrated with Smallpox/Rash Analysis): Resolves exterior muscle heat. For initial fever where toxic heat is excessive, it can also be used to push out smallpox/rash toxins; however, it is contraindicated for cold syndromes occurring after the rash eruption. It specifically governs the Liver and Gallbladder channels. These channels belong to the "clean" fu organs, located at the half-exterior half-interior level, lacking direct pathways for exit or entry, where wind pathogens accumulate. When sweating, vomiting, or purging methods are contraindicated, this herb is used for harmonization. If the goal is to raise yang and soothe the liver, reliance on Chai Hu is necessary to achieve success.
Commentary: Chai Hu is an herb for the half-exterior half-interior aspect of the Shaoyang channel. In malaria cases where fever is intense like fire and the patient is emaciated with visible bones, this condition is named Lao Malaria (Consumptive Malaria). The heat emanates from the marrow; adding harsh/gu-strength agents would further deplete qi and blood, making Chai Hu indispensable for cure. If the disease is in the Taiyang channel, using it too early is like inviting thieves inside. For diseases in the Yin channels, using Chai Hu severely damages the exterior. Laypeople, lacking understanding, mix interior and exterior treatments, which may hide their incompetence but results in countless deaths. For those with qi deficiency, using Chai Hu merely aids the power of Ginseng (Renshen) and Astragalus (Huangqi) in small amounts; it is not Chai Hu itself that reduces fever. If used indiscriminately for consumptive diseases, death is inevitable. Only for consumptive diseases located in the Liver channel is there a specific type, Yin Chai Hu, which is white and soft, specifically managing Liver consumptive disorders and the wasting fevers associated with the five types of childhood malnutrition (Gan syndromes); this is distinct from Xiao Chai Hu Tang (Minor Bupleurum Decoction).