（见肝部补阵）
〔害〕肾虽虚，而火炽者不用。
〔利〕甘辛温，入肝肾。强筋壮骨，益肾添精，治腰膝疼痛，利遍体机关，亦治阴下湿
痒，
小便淋沥。
〔修治〕二、五、六、九月采皮，凡使削去粗皮锉，或酥炙、酒炙、蜜炙、盐酒炒、姜
汁炒
、断丝用。产湖广，湖南者佳。色黄，皮薄，肉浓，如色黑、皮浓、肉薄，不堪用。
〔害〕新刮之甲有毒，不宜频使，妊妇不宜用。病患虚而无热者，不宜用。凡入丸散，
须研
极细，不尔留滞肠胃，能变症瘕。
〔利〕咸寒至阴，属金与水，补心增智慧，益肾阴，治阴虚血弱，劳热骨蒸等症。又能
固大
肠，止泻利。龟胶补阴之力更胜。
龟鹿皆长年，龟首藏向腹能通任脉，取下甲以补肾，补血，皆阴也。鹿鼻反向尾，能通
督脉
，取上角以补火，补气，皆阳也。
〔修治〕采无时，以自败大者力胜，得阴气更全也。酥炙，或酒炙，醋炙，猪脂炙，
灰用
。
龟板洗净，捶碎水浸三日，用桑柴火熬成胶名龟胶，合鹿角胶，一阴一阳，名龟鹿二仙胶。
治真元亏损，精气枯竭，瘦弱少气，目视不明，梦遗泄精，腰腿无力。此能大补精髓，益气
养神。
龟尿走窍，透骨染须发，治哑声。取龟尿法，以镜照之，龟见其影，则淫发而尿出，今
人或
以猪棕、松毛刺其鼻，溺亦出。
(See the Tonifying Array of the Liver section)
[Harm] Although the Kidney is deficient, it should not be used when Fire is blazing.
[Benefits] Sweet, acrid, and warm in nature; enters the Liver and Kidney meridians. Strengthens sinews and bones, tonifies Kidney essence, treats pain in the lower back and knees, facilitates movement of all joints in the body, and also treats dampness and itching in the genital area, as well as dribbling urination.
[Processing and Collection] Harvest the bark in the second, fifth, sixth, and ninth lunar months. When used, scrape off the rough outer bark and chop into pieces. It may be processed with animal fat (Su), wine, honey, salted wine, or ginger juice, and the fibrous strands must be cut off. Produced in Huguang region, with those from Hunan being superior. Those that are yellow, have thin bark, and thick flesh are good; if black, with thick bark and thin flesh, they are unsuitable for use.
[Harm] Freshly scraped turtle shell contains toxins and should not be used frequently; pregnant women should avoid it. Patients who are deficient without heat signs should also avoid it. When incorporated into pills or powders, it must be ground extremely fine; otherwise, it may stagnate in the gastrointestinal tract and cause the formation of masses (Zheng Jia).
[Benefits] Salty and cold in nature, belonging to extreme Yin, associated with Metal and Water elements. Nourishes the Heart and enhances wisdom, tonifies Kidney Yin, treats conditions such as Yin deficiency with blood weakness and tidal fever with bone-steaming sensation. It can also secure the Large Intestine and stop diarrhea and dysentery. Gui Jiao (Turtle Shell Glue) has a stronger Yin-nourishing effect.
Both turtles and deer are long-lived animals. The turtle retracts its head into its abdomen, connecting with the Ren Mai (Conception Vessel); using its shell tonifies Kidney and nourishes Blood, both being Yin aspects. The deer's nose faces backward toward its tail, connecting with the Du Mai (Governing Vessel); using its antlers tonifies Fire and Qi, both being Yang aspects.
[Processing and Collection] There is no fixed time for collection; naturally deceased large turtles yield stronger efficacy as they retain more complete Yin Qi. Can be processed with animal fat (Su), wine, vinegar, pork lard, or calcined into ash.
Wash the Gui Ban (Turtle Shell), crush it, soak in water for three days, and decoct using mulberry wood fire to form glue, named Gui Jiao (Turtle Shell Glue). Combined with Lu Jiao Jiao (Deer Antler Glue), representing one Yin and one Yang, it is named Gui Lu Er Xian Jiao (Two Immortals Glue of Turtle and Deer). It treats depletion of True Yuan, exhaustion of Essence and Qi, emaciation with shortness of breath, blurred vision, nocturnal emission, seminal leakage, and weakness in the waist and legs. This formula greatly tonifies Essence and Marrow, benefits Qi, and nourishes the Spirit.
Gui Niao (Turtle Urine) travels through orifices, penetrates bones, and can darken beard and hair; it treats aphonia. The method to obtain turtle urine is to shine a mirror on it; seeing its reflection causes sexual arousal and urination. Nowadays, some people prick its nose with pig bristles or pine needles to induce urination.