味甘，微寒，无毒，宜酒水各半煮透。连汁晒干，再蒸再晒，九次为度，铜铁皆
忌。如入脾虚剂中，宜炒干用，有痰者姜汁拌炒用。
熟地大补血衰，倍滋肾水，填骨髓宜真阴，专补肾中元气，兼疗藏血之经，折跌绝
筋伤中，五劳七伤血痹，五脏内伤，补绝纹
断，通血脉益气力，聪耳目乌须发，退虚热而润燥，补精血而调经。伤寒后，胫腹最痛
者殊功，新产后脐腹急痛者立效。浊中浊者坚强骨髓，内伤之病肝筋肾骨受之。熟地专
滋肝肾，而内伤筋骨髓肾所之必用也。
主治（痘疹合参）滋肾水补血而益真阴、能安魂魄、治痘血虚无脓。凡痘中痘后
血虚者宜之，盖能补肾中元气，乃天一所生之源也。但性滞而不走，倘脾虚者用必须酒
浸炒之。
按∶熟地黄为补肾要药，养阴上品，六味丸以之为君，天一所生之本也。四物以之
为君，乙癸同源之义也。九蒸九晒方熟，每见世人一煮透便以为熟地误矣。盖禀北方纯
阴之性而生，非太阳与烈火交炼则不熟也。所以固本膏，虽经日煎熬，必生熟各半而用
之，观此可以见矣。如不知此以生地煮熟，便作熟地，投用地黄丸中，则寒凉之性未
除，心肾之经各别，以心经寒凉之药为君主，以肾经温暖之药为臣佐，岂徒无益，反
引寒性，既损真阳，复伤胃气，虚热者暂堪抵受，虚寒者立见沉 。阴受其累，而莫知觉，惜哉！
味甘，性微寒，无毒，适宜用酒和水各一半煮透。连同药汁晒干，再蒸再晒，重复九次为限度，忌用铜器和铁器。如果加入治疗脾虚的方剂中，适宜炒干后使用；有痰湿者用姜汁拌炒后使用。
熟地黄大补血液亏虚，加倍滋养肾水，填充骨髓以固护真阴，专门补益肾中的元气，兼治藏血的经脉，治疗跌打损伤导致的筋断骨折，以及五劳七伤、血痹、五脏内伤等症，能修补断裂的脉络，通畅血脉，益气力，使耳目聪敏，须发变黑，退除虚热并滋润燥邪，补充精血并调理月经。伤寒病后，小腿和腹部疼痛严重者，此药功效显著；新产后脐腹急痛者，服用后立即见效。作为浊中之浊品，它能坚固骨髓，内伤疾病多由肝筋、肾骨受邪所致。熟地黄专门滋养肝肾，而内伤涉及筋骨骨髓的疾病必须使用它。
主治（结合痘疹理论）：滋补肾水，补血以增益真阴，能够安定魂魄，治疗因痘疹导致血虚无脓的情况。凡是痘疮过程中或痘疮后期出现血虚症状者适宜使用，因为它能补益肾中元气，这是天一（先天之本）产生的源头。但它的性质滞涩而不走窜，如果脾虚者使用，必须经过酒浸炒制。
按语：熟地黄是补肾的要药，养阴的上品。六味丸以它为君药，体现了天一所生的根本道理。四物汤以它为君药，体现了乙癸同源（肝肾同源）的含义。只有经过九次蒸煮和九次晾晒才算制成熟地，常常见到世人只煮一次便认为是熟地，这是错误的。因为熟地黄禀受北方纯阴的性质而生，如果不是经过太阳（指火制过程中的温和加热）与烈火的交相炼烤，就不能算作“熟”。所以固本膏虽然经过长时间的煎熬，也必须生地和熟地各半使用，从这一点就可以看出其中的道理。如果不知道这个道理，把生地煮熟了就当作熟地，投入到地黄丸中使用，那么寒凉的药性就没有去除，心经和肾经的药性各自分离，以心经寒凉的药物作为君主药，以肾经温暖的药物作为臣佐药，这不仅没有益处，反而引入寒性，既损伤了真阳，又伤害了胃气。阴虚发热者暂时还能忍受，但阳虚畏寒者立刻会出现沉疴重症。阴分受到牵连，却无人察觉，真是可惜啊！
The flavor is sweet, the nature is slightly cold, and it is non-toxic. It is suitable to be thoroughly decocted with half wine and half water. After drying the liquid together in the sun, steaming and sun-drying should be repeated nine times as the limit. Copper and iron vessels must be avoided. If incorporated into formulas for Spleen deficiency, it should be stir-fried until dry; for patients with phlegm, it should be stir-fried with ginger juice.
Shu Di Huang (Prepared Rehmanniae Radix) greatly tonifies blood deficiency, doubles the nourishment of Kidney Water, fills the bone marrow to consolidate True Yin, specifically tonifies the Yuan Qi within the Kidneys, and concurrently treats the meridians that store blood. It addresses injuries from falls and fractures involving severed tendons, as well as the five labors and seven injuries, blood bi syndromes, and internal injuries of the five zang organs. It repairs broken vessels, unblocks blood vessels, benefits qi and strength, sharpens hearing and vision, darkens hair, clears deficient heat, moistens dryness, replenishes essence and blood, and regulates menstruation. For post-typhoid fever cases where the shins and abdomen are most painful, it shows remarkable efficacy; for acute abdominal pain after recent childbirth, it produces immediate results. As a substance among turbid substances, it strengthens the bone marrow. Internal injury diseases often affect the liver tendons and kidney bones. Shu Di Huang specifically nourishes the Liver and Kidneys, and is essential for internal injuries affecting tendons, bones, marrow, and kidneys.
Indications (Integrated with Smallpox Theory): Nourishes Kidney Water, tonifies blood to benefit True Yin, can calm the soul and spirit, and treats smallpox lesions lacking pus due to blood deficiency. It is suitable for those with blood deficiency during or after smallpox, as it tonifies the Yuan Qi of the Kidneys, which is the source generated by Tian Yi (Heavenly One/Primordial Origin). However, its nature is stagnant and does not circulate freely. If used by those with Spleen deficiency, it must be soaked in wine and stir-fried.
Commentary: Shu Di Huang is an essential herb for tonifying the Kidneys and a superior agent for nourishing yin. In Liu Wei Di Huang Wan (Six-Ingredient Pill with Rehmannia), it serves as the sovereign drug, reflecting the principle of Tian Yi as the root. In Si Wu Tang (Four Substance Decoction), it serves as the sovereign drug, reflecting the principle that Yi and Gui share the same source (Liver and Kidney share the same origin). Only through nine steamings and nine sun-dryings is it properly prepared. It is common to see people mistakenly consider simply boiled Rehmannia as Shu Di Huang. This is incorrect because Shu Di Huang inherits the pure yin nature of the North; without the refining process of sunlight (gentle heating) and fierce fire, it cannot become "cooked." Therefore, in Gu Ben Gao (Solidify the Root Paste), although subjected to prolonged simmering, raw and prepared Rehmannia must be used in equal halves. This illustrates the point. If one fails to understand this and uses cooked Sheng Di Huang (Raw Rehmanniae Radix) as Shu Di Huang in Rehmannia pills, the cold-natured property remains unremoved. The medicinal properties for the Heart meridian and Kidney meridian become separated: using cold-natured drugs for the Heart meridian as sovereigns, while using warm-natured drugs for the Kidney meridian as ministers and assistants. This not only yields no benefit but also introduces coldness, damaging both True Yang and Stomach Qi. Those with deficient heat may temporarily endure it, but those with deficient cold will immediately suffer severe illness. The Yin aspect suffers silently, unnoticed. What a pity!