宣、去风寒湿。
辛温雄壮。为太阳经风药。（膀胱。）寒郁本经。头痛连脑者。必用之。（凡巅顶痛、宜
本
防风、酒炒升柴。）治督脉为病。脊强而厥。（督脉并太阳经、贯脊、又能下行去湿。治妇人
疝瘕。阴寒肿痛。腹中急痛。（皆太阳经寒湿、胃风泄泻。夏英公病泄、医以虚治、不效、
霍翁曰∶此风客于胃也、饮以 本汤而愈、盖 本能除风湿耳。）粉刺酒 。和白芷、作面
脂良。）按头痛挟内热及伤寒。发于春夏。阳证头痛。不宜进也。根紫色。似芎 而轻虚。
气香味麻。恶 茹。（小儿疥癣、 本煎汤浴、并浣衣。）
宣通利湿、消暑退热。
辛散皮肤之蒸热。温解心腹之凝结。属金水而主肺。为清暑之主药。肺气清。则小便行
而热
降。（暑必兼湿、治暑必兼利湿、若无湿、但为干热、非暑也。）治呕逆水肿。
（熬膏服、小便利则消。）香港脚口气。（煎汤含漱。）单服治霍乱转筋。香薷乃夏月解表之品。
无表邪者戒之。（其性温热、阴暑宜用以温散、若阳暑、则宜清凉、误服之、反成大害、
时珍曰∶有处高堂大厦、纳凉太过、饮冷太多、阳气为阴邪所遏、反中入内、遂病头痛恶寒
、烦躁口渴、吐泻霍乱、宜用之以发越阳气、散邪和脾则愈、若饮食不节、劳役作丧之人、
伤暑、汗出如雨、烦躁喘促、或泻或吐者、乃内伤之证、宜用清暑益气汤、人参白虎汤之类
、以泻火益元、若用香薷、是重虚其表、而益之热矣。今人谓能解暑、概用代茶、是开门
揖盗也。）陈者良。宜冷服。（经所谓治温以清凉而行之也、热服作泻。小儿发迟、陈者二
两、水一盏、煎汁三分、入猪脂半两和涂、白秃惨痛、加胡粉和涂。）
To promote circulation and unblock, to dispel wind-cold-dampness.
Pungent and warm in nature, potent and vigorous in action. It is a wind-dispelling herb of the Taiyang channel (Bladder channel). When cold pathogen stagnates in this channel causing headache extending to the brain, it must be used. (For vertex pain, Fangfeng [Saposhnikoviae Radix], Jiuchao Shengma [Aucklandiae Radix processed with wine], and Jiuchao Chaihu [Bupleuri Radix processed with wine] are suitable.) It treats diseases of the Du vessel characterized by stiffness of the spine and厥逆 (cold extremities/fainting). (The Du vessel runs parallel to the Taiyang channel, penetrates the spine, and can descend to dispel dampness; it treats gynecological conditions such as hernia masses, swelling and pain due to yin-cold, and acute abdominal pain.) (These are all caused by cold-dampness of the Taiyang channel and stomach-wind diarrhea. Xia Yinggong suffered from diarrhea; physicians treated him for deficiency without effect. Huo Weng said: "This is wind pathogen lodging in the stomach." He was cured by drinking Xiangru Decoction, because Xiangru can eliminate wind-dampness.) For acne vulgaris, decocted Xiangru in wine mixed with Baizhi [Angelicae Dahuricae Radix] makes an excellent facial cream. Note: Headache accompanied by internal heat and Shanghan (Cold Damage), occurring in spring and summer, belongs to yang-pattern headache, and should not be administered. The root is purple, resembling Xiong [Chuanxiong Rhizoma] but lighter and void in texture. It has an aromatic odor and a numbing taste. It is incompatible with Rucao [Rumex japonicus]. (For pediatric scabies and tinea capitis, Xiangru decoction is used for bathing and laundry.)
To promote circulation, unblock dampness, relieve summerheat, and reduce fever.
Its pungency disperses steaming heat from the skin; its warmth resolves coagulation in the heart and abdomen. It corresponds to Metal and Water and governs the Lung. It is the principal herb for clearing summerheat. When Lung qi is clear, urination flows freely and heat descends. (Summerheat always combines with dampness; treating summerheat requires promoting diuresis to drain dampness. Without dampness, there is only dry heat, which is not summerheat.) It treats vomiting, regurgitation, edema, and Hongkong foot (tinea pedis/erythema ab igne) with bad breath. (Decoct and gargle.) Taken alone, it treats cholera with muscle cramps. Xiangru is an exterior-resolving agent for summer. It is contraindicated in cases without exterior pathogens. (Its nature is warm and hot; Yin-summerheat is suitable for treatment with its warming dispersion. If Yang-summerheat occurs, cooling methods are appropriate; misusing it causes great harm. Li Shizhen said: "Some people stay in high, cool buildings, over-cool themselves, and consume too much cold drink. Their yang qi is suppressed by yin pathogenic factors, allowing pathogens to enter inward, resulting in headache, aversion to cold, restlessness, thirst, vomiting, diarrhea, and cholera. In such cases, Xiangru should be used to vent yang qi, disperse pathogens, and harmonize the spleen, leading to recovery. However, for those injured by irregular diet or overwork, suffering from summerheat injury with profuse sweating like rain, restlessness, panting, diarrhea, or vomiting, these are interior-injury patterns. They should be treated with formulas like Qingshu Yiqi Tang [Clear Summerheat and Boost Qi Decoction] or Renshen Baitu Tang [Ginseng and White Tiger Decoction] to purge fire and benefit yuan qi. Using Xiangru here would further deplete the exterior and add heat. Nowadays, people believe it resolves summerheat and use it generally as tea, which is like opening the door to invite thieves.") Aged Xiangru is superior. It should be taken cold. (As stated in the classics, warm diseases should be treated with cooling methods administered appropriately; taking it hot causes diarrhea. For delayed hair development in children, two liang of aged Xiangru, decocted in one cup of water to yield three-tenths volume, mixed with half a liang of pig fat, applied topically. For painful white tinea capitis, add Hufen [Lead Carbonate] and apply.)