味辛、咸，性寒。入胃、肾二经。
降火，清热。治天行火症，止躁狂出血，口干齿衄，丹投紫雪。
此药与石膏相仿，但能入肾，故降火之力更着，能直达下焦。
味咸，性寒，入脾、胃二经。
清热定惊，平喘通络。火症高烧，神昏抽搐。半身不遂，肢体麻木。风阳上扰、蒙蔽头
目。
此物易霉易蛀，若已霉蛀者，万不可再用。
味苦，性寒，无毒。入心经。龙骨、连翘为使。恶菊花、玄参、芫花、白藓皮、白僵蚕。
畏
款冬、牛膝。解巴豆、附子毒。忌猪肉。姜汁炒。
体阴质燥，清热除湿。泻心除痞满，明目理疮疡。痢疾腹疼，心痛惊烦。杀虫安蛔，利
水浓肠。
禀清寒之气，直泻丙丁，痞满、目疾、疮疡、惊痛，南方亢上之象。泄痢、蛔虫，湿热
之愆
固宜痊也。韩 曰∶“黄连与官桂同行，能使心肾交于顷刻。”
时珍曰∶“香连丸用黄连、木香。木火散用黄连、干姜。左金丸用黄连、吴茱萸。姜黄
散用
黄连、生姜。口疮方用黄连、细辛。皆一冷一热，寒因热用，热因寒用，阴阳相济，最得制
方之妙”。
味苦，性寒，无毒。入肾经。恶干漆。盐酒炒。肥浓鲜黄者佳。
泻龙火而救水，利膀胱以燥湿。佐以苍术，理足膝之痹痛。渍以蜜水，漱口舌之生疮。
黄柏泻阴火，除湿热，故治疗如上。昔人谓其补阴者，非其性补益，热去则阴不受伤，
虽谓
之补亦宜。按苦寒之性利于实热，不利于虚热，凡脾虚食少，或泻或呕，或好热，或恶冷，
或肾虚五更泄泻，小便不禁，少腹冷痛，阳虚发热，瘀血停止，产后血虚发热，金疮发热，
痈疽溃后发热，伤寒发热，阴虚小水不利，痘后脾虚小水不利，血虚烦躁不眠等症，法咸忌
之。
Pungent, salty, cold in nature. Enters the Stomach and Kidney meridians.
Descends fire, clears heat. Treats epidemic fire syndromes (epidemic febrile diseases), stops manic bleeding, dry mouth, and dental epistaxis (gum bleeding); combined with Zixue San (Purple Snow Powder) for treating erysipelas.
This herb is similar to Gypsum Fibrosum (Shigao), but it can enter the Kidney, thus its power to descend fire is more pronounced, reaching directly to the Lower Jiao.
Salty, cold in nature. Enters the Spleen and Stomach meridians.
Clears heat and calms fright, relieves asthma and unblocks collaterals. For high fever due to fire syndromes, coma, and convulsions; hemiplegia, limb numbness. When Wind-Yang harasses upward and obscures the head and eyes.
This substance is prone to molding and insect damage; if already molded or infested, it must absolutely not be used again.
Bitter, cold in nature, non-toxic. Enters the Heart meridian. Dragon Bone (Longgu) and Forsythiae Fructus (Lianqiao) serve as guiding herbs. Incompatible with Chrysanthemi Flos (Juhua), Scrophulariae Radix (Xuanshen), Genkwan Flower (Yuanhua), Dictamni Cortex (Baixianpi), and Bombyx Batryticatus (Baijiangcan). Constrained by Asteris Herba (Kuandong) and Achyranthis Bidentatae Radix (Niuxi). Resolves the toxicity of Crotonis Fructus (Badou) and Aconiti Lateralis Radix Praeparata (Fuzi). Avoid pork. Stir-fry with ginger juice.
Yin in constitution, dry in quality, clears heat and removes dampness. Purges the Heart to relieve fullness, brightens the eyes, and treats sores and ulcers. Abdominal pain due to dysentery, heart pain, palpitations, and restlessness. Kills parasites and calms roundworms, promotes urination and consolidates the intestines.
Endowed with pure cold qi, it directly purges Bing-Ding (Fire element in Five Elements theory). Fullness, eye diseases, sores, and painful spasms are manifestations of excessive Yang rising in the South. Dysentery and roundworms, caused by damp-heat errors, are indeed suitable for recovery. Han stated: "When Coptidis Rhizoma (Huanglian) travels together with Cinnamomi Ramulus (Guigui), it enables the Heart and Kidney to interact within an instant."
Shizhen stated: "Xianglian Wan uses Huanglian and Aucklandiae Radix (Muxiang). Muhsan San uses Huanglian and Zingiberis Rhizoma (Ganjiang). Zuojin Wan uses Huanglian and Evodiae Fructus (Wuzhuyu). Jianghuang San uses Huanglian and Zingiberis Rhizoma Recens (Shengjiang). Mouth ulcer prescriptions use Huanglian and Asari Radix et Rhizoma (Xixin). All involve one cold and one hot, using cold because of heat, using heat because of cold, with Yin and Yang complementing each other, perfectly capturing the subtlety of prescription formulation."
Bitter, cold in nature, non-toxic. Enters the Kidney meridian. Incompatible with Drynariae Rhizoma (Ganqi). Stir-fry with salted wine. Those that are plump, rich, and fresh yellow are superior.
Purges Dragon Fire (Ministerial Fire) to save Water (Kidney Yin), benefits the Bladder to dry dampness. Assisted by Atractylodis Rhizoma (Cangzhu), it treats bi-pain in the feet and knees. Soaked in honey water, used for rinsing the mouth to treat tongue sores.
Phellodendri Cortex (Huangbai) purges Yin Fire and removes damp-heat, hence the treatments mentioned above. Ancients said it tonifies Yin; this is not because its nature is tonifying, but because when heat is removed, Yin is not injured, so calling it a tonic is appropriate. According to its bitter-cold nature, it is beneficial for Excess Heat but detrimental to Deficiency Heat. In cases of Spleen deficiency with poor appetite, diarrhea or vomiting, preference for heat or aversion to cold, Kidney deficiency with dawn diarrhea, urinary incontinence, cold pain in the lower abdomen, Yang deficiency fever, stagnation of blood stasis, postpartum blood deficiency fever, fever from metal wounds, fever after abscesses and ulcers rupture, fever from Cold Damage (Shanghan), Yin deficiency with difficult urination, Spleen deficiency with difficult urination after smallpox, and blood deficiency with irritability and insomnia, these methods should all be avoided.