此为补阴之主方，补五藏之阴以纳于肾也。藏阴亏损，以熟地大滋肾阴，壮水之主以为君。用山萸肉之色赤入心，
味酸入肝者，从左以纳于肾。山药之色白入肺，味甘入脾者，从右以纳于肾。又用三味通府者，恐府气不宣，则气郁生
热，以致消烁藏阴，故以泽泻清膀胱，而后肾精不为相火所摇；又以丹皮清血分中热，则主血之心，藏血之肝，俱不为
火所烁矣。又以茯苓清气分之热，则饮食之精，由脾输肺以下降者，亦不为火所烁矣。夫然后四藏之真阴无所耗损，得
以摄纳精液，归入肾藏，肾受诸藏之精液而藏之矣。从来囫囵看过，未识此方之元妙，至于此极。今将萸肉、山药二味
分看，一入心肝，一入肺脾，既极分明，而气味又融洽。将熟地、萸肉、山药三味总看，既能五藏兼入，不致偏倚，又
能将诸藏之气，尽行纳入肾藏，以为统摄藏阴之主，而不致两歧。至泽泻、茯苓、丹皮与三补对看，其配合之妙，亦与
三补同法。制方妙义，周备若此，非臻于神化者，其孰能之？惟其兼补五藏。故久服无虞偏胜，而为万世不易之祖方也。
此方用附子、肉桂补两肾之阳，非补两肾中之命门也。附子补气中之阳，由肺以入于肾，故阳虚肺气喘急者，服之
即止，乃右肾之阳药也。肉桂补血中之阳，由肝以入于肾，故阳虚肝火上浮者，服之则纳，乃左肾之阳药也。夫从左从
右，非两肾之中，可知命门居中，是以一而神，非以两而化。附子、肉桂，一气一血，两相对待，故非命门药也。如以
附为补命门，则以命门属气，桂不得为补命门矣；以桂为补命门，则以命门属血，附不得为补命门矣。总之，命门为先
天之气，本于始生，为生气、生血之根本，非草根树皮所能补者；药饵入口，从胃气敷布，然后输入肾藏，即系后天饮
食之气所化，但能补益藏腑，不能补益先天。故前人加入地黄丸者，不特附、桂一气、一血，即车前、牛膝亦是一气、
一血，知母、黄柏亦是一气、一血。一气、一血者，俱入两肾，而非命门也。以命门为阳者，此命门与两肾分阴阳，则
命门为阳，两肾为阴。命门为始生之根本，即是万物资始之干元，故为元阳，象坎中之一画也，非以火为阳也。如
以两肾分析而论，则左血为阴，右气为阳，亦非以水火分也。如专以一肾而论，则左肾不独有精，气亦有之，右肾不独
有气，精亦有之，精即为阴，气即为阳，此两肾各有阴阳，故八味地黄丸各补其阴阳也。
这是补阴的主方，通过补益五脏之阴并将其收纳于肾中。若脏阴亏损，便用熟地黄大量滋补肾阴，以“壮水之主”作为君药。使用山茱萸，因其色赤入心、味酸入肝，从左路将阴气纳入肾中；使用山药，因其色白入肺、味甘入脾，从右路将阴气纳入肾中。又配合三味通利腑气的药物，是担心腑气不宣通则会导致气郁化热，进而消烁脏阴，因此用泽泻清利膀胱，使肾精不被相火所扰动；用牡丹皮清泄血分中的热邪，则主血之心和藏血之肝都不被火热灼伤；用茯苓清泄气分中的热邪，则饮食所化生的精微物质，由脾输送至肺并向下沉降的过程，也不被火热灼伤。这样之后，四脏的真阴不再耗损，得以摄纳精液，归入肾脏，肾接受各脏的精液并加以贮藏。以往人们囫囵吞枣地看待此方，未能识得此方奥妙竟达到如此极致。现在将山茱萸、山药两味药分开来看，一味入心肝，一味入肺脾，界限极为分明，且气味又相互融洽。将熟地黄、山茱萸、山药三味药总括来看，既能兼入五脏，不致偏倚，又能将诸脏之气全部纳入肾中，作为统摄脏阴的主药，而不致出现分歧。至于泽泻、茯苓、牡丹皮与前三味补药对照来看，其配伍的妙处，也与三补之法相同。制方的精义，周全完备到这种地步，如果不是达到神化境界的人，谁能做到呢？正因为此方能兼补五脏，所以久服不用担心偏胜之弊，成为万世不可更改的基础方剂。
此方使用附子、肉桂来补益两肾之阳，并非补益两肾中间的命门。附子补益气中之阳，由肺进入肾中，所以对于阳虚导致肺气喘急的患者，服用后即刻见效，它是右肾的阳药。肉桂补益血中之阳，由肝进入肾中，所以对于阳虚导致肝火上浮的患者，服用后能使火气下纳，它是左肾的阳药。所谓从左、从右，并非指两肾中间的位置，由此可知命门居中，是以“一”来显神妙，而非以“两”来生化。附子、肉桂，一气一血，两者相对待，所以它们不是命门药。如果认为附子是补命门的，那就意味着命门属于气，那么肉桂就不能称为补命门了；如果认为肉桂是补命门的，那就意味着命门属于血，那么附子就不能称为补命门了。总之，命门是先天之气，源于生命初始，是生气、生血的根本，不是草根树皮这类药物所能补益的；药物入口后，依靠胃气敷布，然后输入肾脏，这已经是后天饮食之气所化生的，只能补益脏腑，不能补益先天。所以前人加入地黄丸中的药物，不仅仅是附子、肉桂是一气一血的关系，就连车前子、牛膝也是一气一血，知母、黄柏也是一气一血。这些一气一血的药物，都是进入两肾，而不是进入命门。把命门看作阳的观点，是将命门与两肾分别论阴阳，从而认定命门为阳，两肾为阴。命门是生命开始的根本，也就是万物资始的干元，所以称为元阳，象征坎卦中的一画（阳爻），并不是以火来定义阳。如果专门分析两肾，则左血为阴，右气为阳，也不是以水火来区分。如果专就单一肾脏而言，则左肾不仅有精，气也有；右肾不仅有气，精也有，精即为阴，气即为阳，这是因为两肾各自都含有阴阳，所以八味地黄丸分别补益它们的阴阳。
This is the principal formula for tonifying Yin, which tonifies the Yin of the Five Zang organs and guides it into the Kidney. When Zang Yin is deficient, Shu Di Huang (Prepared Rehmannia Root) is used in large doses to greatly nourish Kidney Yin, serving as the Sovereign drug by "strengthening the master of water" (Zhuang Shui Zhi Zhu). Shan Yu Rou (Cornus Fruit), being red in color entering the Heart and sour in taste entering the Liver, guides Yin from the left side into the Kidney. Shan Yao (Dioscorea Rhizome), being white in color entering the Lung and sweet in taste entering the Spleen, guides Yin from the right side into the Kidney. Additionally, three herbs that promote the free flow of Fu organ Qi are used; this is to prevent Qi stagnation due to impaired Fu organ function, which could generate heat and consume Zang Yin. Therefore, Ze Xie (Alisma Rhizome) is used to clear the Bladder, ensuring that Kidney Essence is not disturbed by Ministerial Fire (Xiang Huo); Dan Pi (Moutan Cortex) is used to clear heat from the Blood level, ensuring that the Heart (which governs Blood) and the Liver (which stores Blood) are not scorched by fire; Fu Ling (Poria) is used to clear heat from the Qi level, ensuring that the essence derived from food and drink, transported by the Spleen to the Lung and descending thereafter, is not scorched by fire. In this way, the True Yin of the Four Zang organs is no longer depleted, allowing them to receive and store essence, guiding it into the Kidney. The Kidney then accepts and stores the essence from all other Zang organs. Previously, people viewed this formula superficially and failed to recognize its profound subtlety. Now, viewing Shan Yu Rou and Shan Yao separately: one enters the Heart and Liver, the other the Lung and Spleen; they are distinct yet their flavors harmonize. Viewing Shu Di Huang, Shan Yu Rou, and Shan Yao together: they enter all Five Zang organs without bias, gathering the Qi of various organs into the Kidney to serve as the master regulating Zang Yin, avoiding divergence. Comparing Ze Xie, Fu Ling, and Dan Pi with the three tonifying herbs: their exquisite combination follows the same principle as the three tonics. The ingenuity of this prescription is so comprehensive and perfect that only one who has reached a state of divine transformation could have created it. Because it tonifies all Five Zang organs, long-term use avoids the risk of excess or deficiency in any single aspect, making it an eternal foundational formula.
This formula uses Fu Zi (Aconite Lateral Root) and Rou Gui (Cinnamon Bark) to tonify the Yang of both Kidneys, not the Ming Men (Gate of Life) located between them. Fu Zi tonifies Yang within Qi, entering the Kidney via the Lung; thus, it stops panting and asthma caused by Lung Yang deficiency, acting as the Yang herb for the Right Kidney. Rou Gui tonifies Yang within Blood, entering the Kidney via the Liver; thus, it subdues floating Liver Fire caused by Yang deficiency, acting as the Yang herb for the Left Kidney. The terms "from the left" and "from the right" do not refer to the center between the two Kidneys, indicating that the Ming Men is central, manifesting spirit through unity rather than differentiation through duality. Fu Zi and Rou Gui represent Qi and Blood respectively, standing in opposition; therefore, they are not herbs for the Ming Men. If Fu Zi were considered to tonify the Ming Men, implying the Ming Men belongs to Qi, then Rou Gui could not be said to tonify the Ming Men. Conversely, if Rou Gui were considered to tonify the Ming Men, implying the Ming Men belongs to Blood, then Fu Zi could not be said to tonify the Ming Men. In summary, the Ming Men represents Pre-Heaven Qi, originating at conception, serving as the root of generating Qi and Blood; it cannot be tonified by roots and barks. Medications enter the mouth, are distributed by Stomach Qi, and then input into the Kidneys; they are transformed from Post-Heaven dietary Qi and can only tonify Zang-Fu organs, not Pre-Heaven essence. Thus, in previous additions to the Di Huang Wan formulas, not only are Fu Zi and Rou Gui a pair of Qi and Blood, but also Che Qian Zi (Plantago Seed) and Niu Xi (Achyranthes Root), as well as Zhi Mu (Anemarrhenae Rhizome) and Huang Bai (Phellodendron Bark), are pairs of Qi and Blood. These Qi-Blood paired herbs enter the two Kidneys, not the Ming Men. Those who view the Ming Men as Yang divide Yin and Yang between the Ming Men and the two Kidneys, assigning Yang to the Ming Men and Yin to the Kidneys. The Ming Men is the root of initial life, equivalent to the Creative Force (Qian Yuan) that initiates all things, hence called Original Yang (Yuan Yang), symbolized by the single solid line in the Kan trigram (Water), not defined by Fire. If analyzing the two Kidneys separately, Left Blood is Yin and Right Qi is Yang, distinguishing them not by Water and Fire. If considering a single Kidney, the Left Kidney contains both Essence and Qi, and the Right Kidney contains both Qi and Essence; Essence is Yin, Qi is Yang. Since each Kidney contains both Yin and Yang, Ba Wei Di Huang Wan (Eight-Ingredient Rehmannia Pill) tonifies their respective Yin and Yang.