〔害〕虽能泄肾中之热，除湿热生虫为厉，然气味苦寒，能损肾气，肝肾虚而无热者勿
服。
火衰精冷，真元不足，及年高之人，皆不宜服。
沈括《梦溪笔谈》云∶久用苦参擦牙，遂病腰痛，由其气伤肾故也。
〔利〕苦寒，入肾。除热祛湿，治痈肿疮疡，肠 下血，兼能利水，固齿明目，祛风杀
虫。
苦参子，一名鸦胆子。治肠风下血，能清肝明目，功同槐实。
〔修治〕八月采子，十月采根，曝干，糯米浓泔一宿，其腥秽气并浮在水面上，须重重
淘过
，即蒸三时，取晒切用。
〔害〕大寒凉润，必燥结有实火者，方可用。否则恐寒中，余同干地黄。
〔利〕苦寒微甘，大泻心肾实火，平血逆，除大热。
〔修治〕掘取鲜根洗净，竹刀切片，或捣汁用。
〔害〕气香而浊，极易作呕，胃弱服之即吐，凉血通瘀，故胃气虚寒，妇人血崩，经行
过期
不净，并妊娠者并忌之。若无瘀而血热妄行，及血虚而无外感者，皆不可用。
〔利〕苦辛微寒，入手足少阴厥阴血分，凉血去瘀生新，泻血中伏火，退无汗骨蒸。
治相火之功，胜于黄柏。红花者利，白花者补，宜分别之。
〔修治〕牡丹惟取白红单瓣者入药。二八月采根阴干，以铜刀劈破去骨，肉浓者佳。锉
如大
豆许，用酒细拌蒸干用，或切片酒炒用。
【苦参】
【危害】虽然能够清泄肾中的热邪，消除因湿热滋生虫毒引起的恶疾，但其气味苦寒，会损伤肾气，肝肾虚弱且无热邪者禁止服用。
阳气衰微、精液寒冷、真元不足，以及年事高的人，都不适宜服用。
沈括在《梦溪笔谈》中说：长期用苦参擦牙，导致腰痛，是因为其药气损伤了肾脏的缘故。
【功效】性味苦寒，归肾经。清除热邪、祛除湿气，治疗痈肿疮疡，肠道下血，同时能利水，坚固牙齿、明目，祛风杀虫。
苦参子，又名鸦胆子。治疗肠风下血，能清肝明目，功效与槐实相同。
【炮制】八月采集种子，十月采集根部，晒干后，用浓糯米泔水浸泡一夜，腥秽之气浮在水面上，必须反复淘洗，然后蒸三个时辰，取出晒干切片使用。
【鲜生地】
【危害】大寒凉润，只有大便燥结且有实火者，才可以服用。否则恐怕会导致寒中（寒气直中脏腑），其余禁忌同干地黄。
【功效】性味苦寒微甘，大力泻除心肾的实火，平抑血逆，清除大热。
【炮制】挖掘新鲜的根洗净，用竹刀切片，或者捣取汁液使用。
【牡丹皮】
【危害】气味香而浊，极易引起呕吐，胃弱的人服用后立即呕吐。因其具有凉血通瘀的功效，所以胃气虚寒、妇女血崩、月经过期不净以及孕妇都忌服。如果没有瘀血而是血热妄行，以及血虚而没有外感邪气的，都不可使用。
【功效】性味苦辛微寒，入手少阴、足少阴及厥阴经的血分，凉血去瘀生新，泻除血中伏火，退去无汗骨蒸。在治疗相火方面的功效，胜过黄柏。红花牡丹皮偏于利泄，白花牡丹皮偏于补益，应当加以区分。
【炮制】牡丹皮只选用白红单瓣的品种入药。二八月采集根部阴干，用铜刀劈开去掉木心，肉质厚实的为佳。锉成大豆大小，用酒细细拌匀蒸干后使用，或者切片后用酒炒制使用。
[Kushen]
[Harm] Although it can drain heat from the Kidney and eliminate diseases caused by damp-heat generating parasites, its bitter and cold nature damages Kidney Qi. It is contraindicated for those with Liver and Kidney deficiency without heat.
It is unsuitable for individuals with declining Fire (Yang), cold essence, insufficiency of True Yuan (True Origin), and the elderly.
Shen Kuo in *Dream Pool Essays* stated: Long-term use of Kushen to brush teeth leads to lower back pain, as its qi injures the Kidney.
[Benefits] Bitter and cold; enters the Kidney meridian. Clears heat, dispels dampness, treats carbuncles, sores, ulcers, and intestinal bleeding. It also promotes urination, strengthens teeth, improves vision, dispels wind, and kills parasites.
Kushen Zi (Seeds of Sophora flavescens), also known as Yaduanzi (Brucea javanica). Treats intestinal wind with bleeding; clears the Liver and improves vision; its efficacy is similar to Huai Shi (Sophorae Fructus Immaturus).
[Processing] Collect seeds in August, roots in October. Sun-dry them, then soak overnight in thick rice water. The foul odor will float on the surface; wash repeatedly until clean. Then steam for three shichen (6 hours), sun-dry, and slice for use.
[Xian Shengdi]
[Harm] Extremely cold, cool, and moistening. It should only be used for cases with dry stool accumulation and excess fire. Otherwise, it may cause Cold to strike directly into the interior (Han Zhong). Other contraindications are the same as Gan Dihuang (Dried Rehmanniae Radix).
[Benefits] Bitter, cold, and slightly sweet; strongly drains excess Fire from the Heart and Kidney, subdues rebellious Blood, and eliminates severe heat.
[Processing] Dig up fresh roots, wash clean, slice with a bamboo knife, or crush to extract juice for use.
[Mudanpi]
[Harm] Fragrant yet turbid; easily induces vomiting. Those with weak Stomach Qi will vomit immediately upon ingestion. Due to its ability to cool Blood and promote blood circulation to remove stasis, it is contraindicated for those with Stomach Qi deficiency and Cold, women with metrorrhagia (uterine bleeding), irregular menstruation with prolonged duration, and pregnant women. It is also unsuitable for those with spontaneous bleeding due to Blood Heat without stasis, or Blood Deficiency without external pathogenic invasion.
[Benefits] Bitter, acrid, and slightly cold; enters the Blood aspect of the Hand-Shaoyin, Foot-Shaoyin, and Jueyin meridians. Cools Blood, removes stasis, generates new Blood, drains latent Fire in the Blood, and relieves bone-steaming fever without sweating. Its efficacy in treating Ministerial Fire (Xiang Huo) surpasses that of Huangbai (Phellodendri Cortex). Red-flowered Mudanpi is draining, while white-flowered Mudanpi is tonifying; they must be distinguished.
[Processing] Only single-petaled red or white varieties of Mu Dan are used medicinally. Collect roots in the second and eighth lunar months and dry in the shade. Split open with a copper knife, remove the woody core. Those with thick flesh are superior. Cut into pieces the size of soybeans, mix thoroughly with wine, steam until dry, or slice and stir-fry with wine for use.