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Prepared Rehmannia Root is the dried tuberous root of the Scrophulariaceae plant Rehmannia, processed by steaming and drying. It is produced nationwide, with the best quality from Henan. The original plant is mostly cultivated or wild on hillsides and wastelands by roadsides. It prefers a warm climate, is relatively cold-resistant, and thrives best in sunny, deep, loose, fertile, neutral, or slightly alkaline sandy loam. It has a sweet taste and warm nature. It belongs to the liver and kidney meridians. Its effects include tonifying blood, enriching yin, and benefiting essence and marrow. Clinical names include Prepared Rehmannia Root and Prepared Rehmannia Root Charcoal.

bubble_chart Compendium of Materia Medica

Bencao Yanyi: "The Classic only mentions dry and raw types, not the cooked ones. For conditions like blood deficiency, postpartum deficiency heat, and old philtrum deficiency dryness-heat, Rehmannia is needed. Raw and dry types are often considered too cold, hence the later use of the cooked type."

"Medicinal Properties and Images": Cold in nature, bitter in taste.

When soaked in wine and steamed for a long time, it becomes like black gold. With the power of wine, it becomes slightly warm. It is essential for those with severe blood deficiency and blood decline. It is good for blackening hair. It is strictly forbidden to eat radishes.

"Medicinal Property Rhyme": Sweet and bitter in taste, warm in nature, non-toxic. It is heavy and yin. Its uses include activating blood qi, filling the marrow; nourishing kidney qi, supplementing true yin; severe pain in the thighs after cold-damage disease, and unbearable pain in the navel and abdomen after childbirth.

Tangye Bencao: Cold in nature, bitter in taste, yang within yin. Slightly sweet and bitter, thick in taste, thin in qi, yang within yin. Non-toxic.

It enters the hand and foot Shaoyin meridians and the Jueyin meridian.

"Image" says: Soaked in wine, steamed like black gold, with the power of wine, it becomes slightly warm. It is a great tonic, necessary for those with blood decline. It is good for blackening hair, avoid radishes.

"Treasure" says: For external or upper body treatment, use wine-processed.

"Heart" says: Raw, it is very cold and cools blood; cooked, it is cold and tonifies the kidney.

"Materia Medica" says: It treats broken tendons, internal injuries, expels blood stasis, fills the marrow, and grows muscles. As a decoction, it removes cold and heat, abdominal masses, and impediments. It treats men's five strains and seven injuries, women's internal injuries, vaginal bleeding during pregnancy, breaks evil blood, and stops bleeding. It benefits the large and small intestines, removes retained food in the stomach, strengthens the weak, tonifies the five zang-organs' internal deficiencies, unblocks blood vessels, tonifies qi, and clears the ears and eyes. The raw form is especially good. It is best with clear wine and Ophiopogon Tuber. It is incompatible with Fritillaria Bulb and fears large-fruited elm.

Dongyuan says: Unprocessed Rehmannia Root treats heat in the palms and soles, and heart heat. It enters the hand and foot Shaoyin and Jueyin meridians, benefits kidney water, and treats blood. It is suitable for those with strong pulses. For weak pulses, Prepared Rehmannia Root is better. Rehmannia, steamed nine times with fire, can tonify the kidney's original qi. Zhang Zhongjing's Eight Flavor Pill uses Prepared Rehmannia Root as the chief herb, the source of heaven's creation. The Four Substances Decoction for treating blood-storing organs also uses dry Prepared Rehmannia Root as the chief herb, as it treats both Gui and Yi. When steaming and pounding, avoid iron, as contact with iron can cause lower consumptive thirst.

Chen Cang-qi says: Steamed and dried, it warms and tonifies; raw and dried, it is neutral and dispersing.

"Essential Mechanisms" says: Prepared Rehmannia Root treats pain below the navel, which is related to the kidney meridian, and only Rehmannia can remove it. For tonifying the kidney and benefiting yin, the Two Suitable Pill with Chinese Angelica is used to supplement the marrow.

Bencao Yanyi Buyi: Cold in nature, bitter in taste, yang within yin, enters the hand Shaoyin meridian. Also known as 苄 and 芑. It is a great tonic, necessary for those with blood decline. It also fills the marrow, grows muscles, treats men's five strains and seven injuries, women's internal injuries, vaginal bleeding during pregnancy, breaks evil blood, and stops bleeding. When first harvested, soak in water; the floating ones are called Tianhuang and are unusable. The semi-sunken ones are called Renhuang and are secondary. The sunken ones are called Rehmannia and are the best. Its flower is the Earth Marrow Flower. It can be taken alone to prolong life. When steaming, use a wooden steamer and earthenware pot, avoid ironware. It can cause lower consumptive thirst, harm men's Rong, and women's Wei.

Bencao Fahui: Jiegu said: Prepared Rehmannia Root, yellow, steamed nine times with wine, slightly warm by the force of wine, tonifying blood deficiency. It must be used by those with deficient blood and weakened constitution. It is good for blackening beard and hair. Avoid garden radish seed. The "Secret of Indications" says: It is warm in nature, bitter and sweet in taste, thin in qi and thick in flavor. It sinks and descends, yin in nature. It has five uses: First, it benefits the true yin of the kidney water; second, it harmonizes postpartum blood and qi; third, it relieves acute pain in the abdomen and navel; fourth, it nourishes yin and reduces yang; fifth, it strengthens the source of water. For external and upper treatments, it is soaked in wine.

Bencao Gangmu: "Jianyi Fang" states: Men often suffer from yin deficiency, and should use Prepared Rehmannia Root. Women often suffer from blood heat, and should use Unprocessed Rehmannia Root. It also says: Unprocessed Rehmannia Root can generate essence and blood, and Asparagus Root leads it to the place where it is generated. Prepared Rehmannia Root can tonify essence and blood, and Ophiopogon Tuber leads it to the place where it is tonified.

Yixue Zhengzhuan (Yu Tuan) states: Unprocessed Rehmannia Root generates blood, but those with weak stomach qi may find it interferes with digestion. Prepared Rehmannia Root tonifies blood, but those with excessive phlegm-fluid retention may find it clogs the diaphragm. Some say: Unprocessed Rehmannia Root stir-fried with wine does not harm the stomach, and Prepared Rehmannia Root stir-fried with ginger does not clog the diaphragm. These are the subtleties of using Rehmannia.

Prepared Rehmannia Root is sticky in nature, but when combined with the fragrant and penetrating Villous Amomum Fruit, it harmonizes the peaceful qi of the five zang-organs and returns to the dantian.

It fills the marrow, expands the muscles, generates essence and blood, tonifies the deficiencies of the five zang-organs, unblocks the blood vessels, clears the ears and eyes, blackens the beard and hair, treats men's five strains and seven injuries, women's vaginal bleeding during pregnancy, irregular menstruation, and various diseases of pregnancy and childbirth.

Bencao Mengquan: Its nature is slightly warm and slightly dispels cold qi, entering the hand and foot Shaoyin and Jueyin meridians. It greatly tonifies blood deficiency, doubly nourishes kidney water, increases strength, brightens the ears and eyes, fills the marrow, and benefits true yin. It is especially effective for the most painful thighs and calves after cold-damage disease, and for acute pain in the navel and abdomen after childbirth. It blackens the beard and hair, beautifies the complexion, and preserves youth. Zhang Zhongjing used it as the main ingredient in the Eight-Ingredient Pill, taking it as the source of life under heaven, specifically tonifying the original qi of the kidneys; as heaven generates water, so the original qi of humans is governed by the kidneys. Li Dongyuan used it as the main ingredient in the Four Ingredients Decoction, combining the treatment of the kidney and liver, and also treating the blood-storing meridians. The kidney belongs to water, the liver belongs to wood, and the liver is the Sea of Blood, hence it is called the blood-storing meridian. Long-term use improves vision and prolongs life.

Mo's note: Zhu Danxi said: Tonifying blood in qi disease, even if it does not hit the mark, is harmless. Reading this, one cannot help but have doubts. Among blood tonics, none surpass Rehmannia and Chinese Angelica, but if taken excessively, their sticky nature can harm stomach qi. I have seen cases of stomach deficiency and weak qi, unable to move, with blood rushing to the upper orifices, using this to form the Four Ingredients Decoction, as a cooling and tonifying blood remedy. Overuse in treatment can lead to chest and diaphragm stuffiness, reduced appetite, vomiting and diarrhea, panting and hematemesis, daily worsening, nearing death. This is all due to blood medicine harming the peaceful stomach qi, how can it be said to be harmless? Generally, blood deficiency should not be treated by solely tonifying qi, and qi deficiency should not be treated by excessively tonifying blood. What is valuable is to accurately recognize the syndrome, measure the dosage, and assist appropriately, so as not to cause undue harm.

"Medicinal Property Explanation": Sweet and bitter in taste, warm in nature, non-toxic, enters the heart, liver, and kidney meridians. Activates blood qi, fills the marrow, nourishes kidney water, tonifies true yin, treats the most painful thighs and calves after cold-damage disease, acute pain in the navel and abdomen after childbirth, clears the ears and eyes, blackens the beard and hair, treats five strains and seven injuries, and calms the soul. Its uses, contraindications, fears, and aversions are the same as Unprocessed Rehmannia Root, and it is especially sticky.

Note: Prepared Rehmannia Root is a top blood tonic, and the heart and liver store and generate blood, hence it can enter them. Its color is black, its nature is heavy and turbid. The classic says: The turbid within the turbid strengthens the marrow. The kidneys govern the bones, hence it enters them. When essence and blood are sufficient, the symptoms of the thighs, calves, and abdomen naturally heal, and the ears, eyes, beard, and hair must benefit. And labor injuries and palpitations can also be cured.

Yaojian: Cold in qi, sweet and bitter in taste, non-toxic, thin in qi and thick in taste, sinking, yin within yang. Because of its cold and sticky nature, it is washed with pure wine, or stir-fried with ginger juice, or used with Aconite Lateral Root, not only to move stagnation but also to conduct into the kidneys. Those with lower yuan blood deficiency must use it. It also fills the marrow and grows muscles. Those with faint pulse at the chi position should use cinnamon and aconite. Those with strong pulse at the chi position should use Phelloendron Bark and Anemarrhena, to nourish yin and reduce fire, tonifying the kidneys. It blackens the beard and hair. Combined with Cervi Deer-Horn Glue, it greatly tonifies blood. But this remedy clogs the diaphragm and should not be used alone. If it comes into contact with iron, it can cause lower consumptive thirst. Avoid radish seeds, as they can deplete blood. Used in pox medicine to regulate qi, but forbidden if there is diarrhea.

Jingyue Quanshu: Sweet and slightly bitter in taste, with a thick flavor and thin qi, sinking in nature, containing yang within yin. Materia medica states that it enters the Jueyin and Shaoyin meridians of the hands and feet, greatly tonifying blood deficiency, nourishing kidney water, filling bone marrow, benefiting true yin, specifically tonifying the original qi of the kidneys, and also treating the meridians that store blood. Although this generally captures its essence, how can it fully express its wonders? Rehmannia is produced in the fertile lands of the Central Plains, where it absorbs the most abundant earth qi. Its color is yellow, the color of earth; its taste is sweet, the taste of earth. Having obtained the qi of the earth, how can it not be a medicine of the Taiyin and Yangming meridians? I do not believe it. However, the raw form is cool in nature, and the spleen and stomach prefer warmth, so those with insufficient spleen yang should use it with caution. As for the cooked form, it is neutral in nature, embodying the virtue of extreme yin, with pure and calm qi and flavor, thus it can tonify the true yin of the five zang-organs, and is most important for the blood-rich organs. Is it not a medicine for the spleen and stomach meridians?

Moreover, the reason why humans have life is due to qi and blood. Qi governs yang and is active, while blood governs yin and is tranquil. For tonifying qi, Ginseng is the primary herb, while Atractylodes can only serve as an adjuvant; for tonifying blood, Prepared Rehmannia Root is the primary herb, while Chuanxiong and Angelica can only serve as adjuvants. However, when it comes to Atractylodes, Chuanxiong, and Angelica, there are certain contraindications, whereas Ginseng and Prepared Rehmannia Root are indispensable for qi and blood. Therefore, for any deficiency of yang qi in the meridians, Ginseng is essential; for any deficiency of yin blood in the meridians, Prepared Rehmannia Root is essential. Ginseng has the function of strengthening and moving, while Prepared Rehmannia Root possesses the virtue of tranquility and compliance. This relationship between Prepared Rehmannia Root and Ginseng, one yin and one yang, complements each other like the exterior and interior, one form and one qi, mutually supporting generation and transformation. Their nature and flavor are balanced and upright, and nothing surpasses them. Truly, there is no substitute or replacement for them.

For all cases of true yin deficiency, symptoms may include fever, headache, intense thirst, pharyngitis, cough with phlegm, or shortness of breath; or cold reversal in the spleen and kidney leading to vomiting, or virtual fire carrying blood to the mouth and nose, or water overflowing to the skin, or yin deficiency with diarrhea, or yang floating with mania and agitation, or prolapse of the uterus with collapse. For yin deficiency with scattered spirit, the stabilizing power of Prepared Rehmannia Root is necessary to gather it; for yin deficiency with rising fire, the heaviness of Prepared Rehmannia Root is necessary to descend it; for yin deficiency with agitation, the tranquility of Prepared Rehmannia Root is necessary to calm it; for yin deficiency with rigidity and urgency, the sweetness of Prepared Rehmannia Root is necessary to relax it. For yin deficiency with water evil flooding, what else but Prepared Rehmannia Root can control it? For yin deficiency with loss of vital qi, what else but Prepared Rehmannia Root can return it to its source? For yin deficiency with damage to both essence and blood, and thinning of the fatty layer, what else but Prepared Rehmannia Root can thicken the intestines and stomach?

Moreover, there is something even more profound and marvelous: Prepared Rehmannia Root, when combined with powder, can induce sweating. Why? Because sweat is transformed from blood, and without yin, there can be no sweat. Prepared Rehmannia Root, when combined with warming agents, can restore yang. Why? Because yang is born from below, and without restoration, there can be no creation. However, yang nature is fast, so a small amount of Ginseng can achieve success; yin nature is slow, so Prepared Rehmannia Root requires a large amount to be effective. Yet, some people today fear its cloying and greasy nature. How then did the Cui family use Kidney Qi Pill to treat phlegm floating? Some fear its slippery and damp nature. How then did Zhongjing use the Eight-Ingredient Pill to treat kidney diarrhea? Some say yang can generate yin, but yin cannot generate yang. However, the principle of yin-yang is inherently interdependent, mutually reinforcing, and neither can be lacking. Without yang, yin cannot be generated; without yin, yang cannot be transformed. Therefore, the Neijing says: Essence transforms into qi. Does this not mean that yin also generates yang? Who says yang can generate, but yin cannot grow?

Furthermore, regarding the methods of preparation, some use ginger juice for stir-frying, which is necessary for cases of cold in the middle with vomiting; some use Villous Amomum Fruit for preparation, which is necessary for cases of distension and stagnation; some use wine for stir-frying, which is necessary for cases of meridian blockage. If these conditions are not present, and one insists on using these preparation methods, it shows a lack of understanding that the purpose of using Prepared Rehmannia Root is to utilize its tranquil and heavy properties, and instead, one disrupts its nature by making it dispersing and moving. Is this not like drawing a snake and adding feet?

Today, some people want to use it for tonifying yin but insist on combining it with diuretics. How can they not know that tonifying yin does not benefit water, and benefiting water does not tonify yin, and that the method of tonifying yin should not involve diuresis? Some use it for tonifying blood but doubt its cloying nature. How can they not know that blood deficiency is like dry soil, desperately longing for rain, and that the parched yang greatly rejoices in moisture? If this is not understood, then even when using a small amount, one still wants to combine it with diuretics. Who would dare to use it alone and in large quantities? If one dares not use it alone and in large quantities, who would dare to further assist it with sweetness to fully utilize its strengths? Is this not like giving up eating for fear of choking? Alas! Alas! The efficacy of Prepared Rehmannia Root has long been unrecognized in contemporary use, and there is much more that cannot be fully expressed in writing. I now specially highlight it, hoping that the wise will come to understand it themselves.

Bencao Beiyao: Balanced tonification of the liver and kidney, nourishing blood and enriching yin.

Sweet and slightly warm. Enters the hand and foot Shaoyin and Jueyin meridians. Nourishes kidney water, supplements true yin, fills bone marrow, generates essence and blood, improves hearing and vision. The ears are the orifice of the kidney, and the eyes are the orifice of the liver. The eyes can see when they receive blood, and the ears can hear when they receive blood. Blackens hair and beard. Treats fatigue, common cold, and various diseases during pregnancy and childbirth. It is a top-grade remedy for tonifying blood. Danxi said: Before childbirth, the focus should be on clearing heat and nourishing blood; after childbirth, the focus should be on greatly tonifying qi and blood. Even if there are miscellaneous symptoms, treat them from the root. Ang notes: Danxi's statement about greatly tonifying qi and blood after childbirth is indeed a most appropriate and unchangeable theory. Later generations did not use it well, often failing to resolve wind-cold or static blood, and recklessly applying drastic tonification, which instead caused great harm. This must be carefully observed. Wang Shuo said: Men often have yin deficiency and should use Prepared Rehmannia Root; women often have blood heat and should use Unprocessed Rehmannia Root. Rehmannia is cold in nature, but becomes warm when combined with wine, fire, or sunlight; it is sticky in nature, but becomes harmonious when combined with Villous Amomum Fruit, and can be guided to the dantian. It is used as the main ingredient in the Six-Ingredient Pill. For those with weak chi pulse, add cinnamon and aconite, which is called benefiting the source of fire to eliminate yin nebula; for those with strong chi pulse, add anemarrhena and phellodendron, which is called strengthening the master of water to control the sunlight.

Benjing Fengyuan: Prepared Rehmannia Root is steamed and sun-dried, transforming bitterness into sweetness, acting as yang within yin, thus it can tonify the original qi of the kidneys. It must be steamed and sun-dried multiple times to obtain the true fire of taiyang, ensuring the wonderful effect of harmonizing water and fire. If it is merely cooked without steaming and sun-drying, what benefit is there in consuming it? Haogu said: Unprocessed Rehmannia Root treats heart heat and palm heat, benefits kidney water, and cools heart blood. It is suitable for those with a strong and full pulse. For those with a deficient pulse, Prepared Rehmannia Root is appropriate. In Qian's Six-Ingredient Pill, it is the principal ingredient, representing the source of heavenly water. For those with inherently weak true fire of the life gate, Cui's Eight-Ingredient Pill is necessary, combining the power of cinnamon and aconite to achieve the dual benefit of yin and yang. In the Four Ingredients Decoction, it is the main ingredient, treating the liver and kidney as sharing the same source. Its function is specifically to replenish marrow, grow muscles, generate essence and blood, tonify the deficiencies of the five zang-organs, unblock meridians, improve hearing and vision, darken hair, treat men's five strains and seven injuries, women's injuries, vaginal bleeding during pregnancy, irregular menstruation, various pregnancy and postpartum diseases, nourish kidney water and true yin, relieve acute pain in the navel and abdomen, post-illness soreness in the thighs and legs, difficulty in rising from a seated position, and blurred vision. Pain below the navel is due to kidney essence damage; soreness in the thighs and legs is due to deficiency of the lower origin; blurred vision is due to water deficiency impairing vision. All these are diseases governed by the kidneys, which cannot be treated without Prepared Rehmannia Root. Nowadays, for treating internal visual obstruction with nebula, the Six-Ingredient Pill is often used with Magnetite and Cinnabar Pill, which is not appropriate. Rehmannia is contraindicated with iron, and magnetite is the mother of iron, so how can it not be avoided? I have used Chinese Angelica instead of Rehmannia, leveraging its acrid warmth to assist in expelling pathogens from the exterior. For excessive fire, Peony Root is used instead of Asiatic Cornelian Cherry Fruit, leveraging its sour cold to astringe the scattered yin. Although the herbs are different, their effects are not dissimilar. Note: Rehmannia is originally a medicine of the hand shaoyin meridian, specializing in clearing heat and dispersing blood. Without steaming and sun-drying, it cannot enter the foot shaoyin meridian. It achieves the coordination between water and fire, transforming bitterness into sweetness and purple into black, thus directly entering the kidneys, drastically tonifying genuine yin, and also nurturing the yellow court and posterior earth. With thick earth carrying all things, all organs benefit from its shade. Thus, Cui's Eight-Ingredient and Qian's Six-Ingredient Pills are the general regulators for nurturing true yin and true yang. Later generations have used these, adjusting according to individual predispositions, and have benefited in all cases. For unconsolidated yin qi, add Puncturevine Caltrop Fruit; for insufficient yang qi, add Pilose Antler and Placenta; for unrelieved middle qi, add Aquilaria and Amomum; for unabsorbed lowering qi, add Achyranthes Root and Plantago; for unmoistened upper qi, add Ophiopogon and Schisandra; for excessive liver qi, reduce Cornus and double Alisma; for essential qi collapse, reduce Alisma and double Cornus, each achieving the wonderful effect of correcting imbalances. For those with excessive yin fire, add Anemarrhena and Phellodendron to the Six-Ingredient formula, which is no different from drinking poison to quench thirst. Others, like Ligusticum and Angelica in the Four Ingredients Decoction, correspond to Cornus and Dioscorea in the Six-Ingredient Pill; Astragalus and Cinnamon in the Ten Complete Great Tonification correspond to Cinnamon and Aconite in the Eight-Ingredient Pill, achieving the wonderful effect of mutual support between yin and yang. It must be understood that the Eight-Ingredient and Ten Complete Pills regulate blood and qi evenly, and the nature and flavor of the decoction are easily excessive. Rehmannia and Ginseng can be used together without issue. In the Six-Ingredient Pill, absolutely no middle energizer herbs should be mixed, such as Ginseng, White Atractylodes Rhizome, or Liquorice Root, as they are all inappropriate. In the past, some added Ginseng to the Six-Ingredient Pill and upon swallowing, immediately felt confused and uncomfortable; or added Ophiopogon Tuber and Schisandra, which greatly enhanced the efficacy, deeply understanding the wonderful effect of mutual generation between metal and water, which is not something that can be discussed with those who are not specialized in medicinal properties.

Bencao Qiuzhen: [Note] Can nourish kidney water.

Prepared Rehmannia Root enters the kidney and also the liver. It is sweet and slightly warm in nature, with a thick taste and thin qi. It specifically nourishes the kidney's normal genuine qi of the zang-organs and also cultivates the yellow court's posterior earth. When the earth is thick, it can carry things, and all the organs benefit from its shade. Therefore, it is also said to be able to nourish the true yin of the five zang-organs. The efficacy of Prepared Rehmannia Root is very significant. Jingyue stated that when there is a deficiency of true yin, it can cause fever, headache, thirst, pharyngitis, cough with phlegm, panting, or cold reversal of the spleen and kidney leading to vomiting. However, there are also cases where Rehmannia should not be used. For example, when deficient fire carries blood to the mouth and nose, or when water overflows on the skin, or when yin deficiency leads to diarrhea, yang floating causing mania, or prolapse of the uterus causing collapse, or when yin deficiency leads to scattered spirit, only the stabilizing nature of Prepared Rehmannia Root can gather and control the dispersion. When yin deficiency causes fire to rise, only the heavy nature of Prepared Rehmannia Root can subdue it; heavy to control the rise. When yin deficiency causes agitation, only the calming nature of Prepared Rehmannia Root can pacify it; calm to control movement. When yin deficiency causes rigidity and urgency, only the sweet nature of Prepared Rehmannia Root can relax it; sweet to control urgency. When yin deficiency causes water evil to boil upwards, only Prepared Rehmannia Root can control it; water to lead water. Only Prepared Rehmannia Root can return to the origin; when yin deficiency causes damage to both essence and blood, and the fat and marrow are thin, only Prepared Rehmannia Root can thicken the intestines and stomach. Thick to nourish the thin. Moreover, there is something even more mysterious and wonderful: Prepared Rehmannia Root, when combined with powder, can induce sweating, as sweat transforms from blood, yin transforming into yang. Without yin, there is no sweat; Prepared Rehmannia Root, when combined with moistening formulas, can restore yang, as yang is born below, leading yang back to yin. Without yin, there is no return. However, yang is fast, so even a small amount of Ginseng can be effective; yin is slow, so Prepared Rehmannia Root requires a large amount to be effective. Nowadays, some people fear its sticky and greasy nature, but why did Cui Shi use it in Kidney Qi Pill to treat floating phlegm? Phlegm originates from the kidney. Some fear its slippery and damp nature, but why did Zhongjing use it in the Eight Flavor Pill to treat efflux diarrhea? Diarrhea is due to insecurity of kidney qi, hence called kidney diarrhea. Some say yang can generate yin, but yin cannot generate yang, but the principle of yin-yang is originally mutually rooted, without yin, yang cannot transform. They mutually reinforce each other, and neither can be lacking. Without yang, yin cannot be generated; without yin, yang cannot transform. Neijing says: Essence transforms into qi, does this not mean yin also generates yang? Jingyue's discussion on Prepared Rehmannia Root is the most clear, but his point that spleen and stomach cold reversal causing vomiting can be treated with Rehmannia is a rare oversight. If there is deficiency-cold of the spleen and stomach, then the spleen and stomach are already burdened by cold, and it is appropriate to use pungent and hot substances to eliminate it. If taiyang arrives, the hard ice will naturally melt, but if frost and snow are added, and yin agents are used, will it not make the cold worse? I read Jingyue Quanshu, and found his discussions to be penetrating and each word to be a rule, which can be followed. However, his discussion on Rehmannia being suitable for spleen and kidney deficiency cold is not comprehensive. Although Prepared Rehmannia Root is warm in nature, and cold can be dispersed by warmth, but when cold rises to cause vomiting, the cold is already severe, how can the warmth of Prepared Rehmannia Root disperse the cold outward? But if yang is strong and yin is weak, and yang relies on yin to transform, occasionally with a common cold, mixing this with warm dispersing agents may have some effect. If there is true pure yin without fire, and qi rises and reverses causing vomiting, then this is deeply contraindicated. As for the preparation and use of Rehmannia, it should be mixed with good wine and Villous Amomum Fruit powder, steamed and dried for a long time, turning bitter to sweet and purple to black, so that it can directly enter the kidney meridian. Wang Ang said: Rehmannia is cold in nature, but becomes warm when combined with wine, fire, and sun. Its stagnant nature is made smooth by Villous Amomum Fruit, and it can be led into the dantian. It is used as the main ingredient in the Six Flavor Pill, with cinnamon and aconite added for weak chi pulse, which is called benefiting the source of fire to eliminate yin nebula; with anemarrhena and phellodendron added for strong chi pulse, which is called strengthening the master of water to control the sunlight.

Depei Bencao: Fears, aversions, and contraindications are the same as those of Unprocessed Rehmannia Root.

Sweet, slightly warm. Slightly bitter. Enters the hand and foot Shaoyin and Jueyin meridians' blood aspect. Tonifies true yin, fills the marrow. For yin deficiency with fire flaring, water transforming into phlegm. Dryness of fluids with no sweating, dysphoria and restlessness, deafness and blurred vision, scattered spirit and qi, thin and depleted essence, difficult urination, unformed stools, wilting impediment and numbness, unresolved old phlegm, and true yang not returning, etc., these conditions cannot be treated without it.

Combined with Smoked Plum, it guides into the marrow; combined with Villous Amomum Fruit, it directs qi back to yin; combined with stir-fried Dried Ginger, it treats postpartum blood clots; combined with Moutan Bark, it enriches yin and cools blood. Used with Scrophularia Root, it eliminates yin fire; combined with Chinese Angelica, it treats fetal pain; added with Achyranthes Root, it treats pain in the lower legs and abdomen due to blood deficiency. Combined with oyster shell, it resolves phlegm from yin fire.

For excessive phlegm, stir-fry with ginger juice; for moving blood, stir-fry with wine; for moistening the intestines, stir-fry with human milk; for directing qi and regulating qi, stir-fry with Villous Amomum Fruit; for reducing fire, boil with child's urine; for consolidating essence, boil with Cherokee Rose Fruit juice; for tonifying the spleen and stomach, stir-fry until scorched to preserve its nature. If it is cooked but not steamed and sun-dried nine times, its cold and cool nature remains, and it only acts as a cooling agent for the heart meridian, damaging stomach yang and stomach qi, and should not be used recklessly. For those with yin deficiency and active fire, a half-raw and half-cooked product is most suitable.

Prepared Rehmannia Root has a sweet and stagnant taste. Sweetness pleases the spleen, and although it nourishes the kidneys, it greatly benefits the earth. The "Classic" states: Excessive sweetness causes kidney qi to be overwhelmed by earth and unable to ascend to the heart, and the heart cannot descend to the kidneys. Kidney qi does not rise but sinks alone, creating imbalance. Sudden death in humans is due to the lack of communication between vital qi, leading to internal collapse. It is appropriate to use pungent and cool agents as guides. Sweetness combined with pungency promotes dispersion, ensuring internal qi flows freely, and the heart and kidneys connect, preventing panting and fullness. Moreover, kidney qi moves without stagnation, essence rises and transforms into qi, and metal qi also arises from water. Lung qi returns to the kidneys, and in tonifying and astringent formulas, it is beneficial to add a small amount of qi-regulating herbs, making the tonic formula more effective.

Shennong Bencao Jing Bai Zhong Lu: Ancient formulas only used Dried Rehmannia Root and Unprocessed Rehmannia Root, never Prepared Rehmannia Root. Prepared Rehmannia Root is a method developed after the Tang dynasty and is quite suitable for adding to warming and tonifying kidney meridian formulas. However, it is not appropriate for decoctions, blood-nourishing, or blood-cooling formulas. Rehmannia is primarily valued for its cool and smooth, flowing nature, which is lost when cooked, becoming cloying and losing its original properties.

Additionally, in Zhang Zhongjing's "Treatise on Cold Damage," among the 113 formulas, only the Pulse-Restoring Decoction uses Rehmannia. In cold damage diseases, pathogens enter from the outside, and stagnation is most feared. Even when using tonics, they must include dispersing and dredging properties to be suitable. Otherwise, pathogenic qi may turn inward, causing lingering harm. Nowadays, people often see a slight sign of deficiency and immediately use Six-Ingredient Decoction as a common remedy, leading to countless deaths, which is deeply lamentable.

Bencao Xinbian: Sweet in taste, warm in nature, sinking, yang within yin, non-toxic. Enters the liver and kidney meridians. Promotes blood production, benefits essence, and strengthens the marrow in bones and the brain. The true yin energy cannot be generated without it, and the flames of deficient fire cannot be subdued without it. It is indeed a miraculous substance for saving lives and a wonderful flavor for prolonging life. People discard it due to its greasy and stagnant nature, unaware of its efficacy. The kidney is to be tonified, not purged, hence the kidney must be tonified. However, there are few medicines that truly tonify the kidney. Apart from Asiatic Cornelian Cherry Fruit, Achyranthes Root, Eucommia Bark, and the northern five flavors, what other medicine can be used besides Prepared Rehmannia Root? Moreover, Asiatic Cornelian Cherry Fruit and Achyranthes Root cannot serve as the sovereign medicinal, and Eucommia Bark is too warm in nature, suitable for tonifying the decline of kidney fire but not for replenishing the deficiency of kidney water. This is why Prepared Rehmannia Root must be used. Prepared Rehmannia Root is a sovereign medicinal, and its dosage can range from one to eight taels. The use of yin-tonifying medicines differs from that of yang-tonifying medicines. Yang-tonifying medicines can achieve effects with a small dosage, while yin-tonifying medicines require a large dosage to be effective. This is because yang governs generation and yin governs descent. With yang generation, a small amount of yang medicine can easily ascend the qi; with yin descent, a small amount of yin medicine makes it difficult for the flavor to reach downward. Prepared Rehmannia Root, being an extreme yin medicine, is particularly different from other yin medicines. Without a large dosage, how can it achieve victory? Some may ask, since Prepared Rehmannia Root is an extreme yin medicine, but it is very stagnant in nature, and using it in large amounts may cause greasiness and phlegm production, potentially leading to dangerous conditions like phlegm-induced asthma. This is precisely because they do not understand the efficacy of Prepared Rehmannia Root. Since Shennong tasted herbs, this flavor has been neglected, causing later generations to be unaware of its benefits. Although many famous physicians throughout history have made discoveries, they have not revealed its secrets. Prepared Rehmannia Root not only does not produce phlegm but can also disperse phlegm; not only does it not stagnate qi but also excels in moving qi. It all depends on how it is used. Phlegm has different origins in the five zang-organs. For phlegm originating from the spleen and lungs, using Prepared Rehmannia Root may exacerbate dampness, making it seem unsuitable. However, for phlegm originating from the heart, liver, and kidneys, what other medicine can expel it besides Prepared Rehmannia Root? Therefore, for those who spit clear water-like phlegm, using Erchen decoction to disperse and resolve phlegm often fails, but taking the Eight Flavor Decoction can immediately calm the surging phlegm qi. Isn't this clear evidence that Prepared Rehmannia Root is effective for phlegm from the heart, liver, and kidneys?

There is another type where, between morning and evening, all that is expectorated is white foam, mild during the day and severe at night, to the extent that one cannot lie down. Using the Six-Ingredient Decoction, significantly adding Prepared Rehmannia Root and Asiatic Cornelian Cherry Fruit, after several doses, the phlegm greatly reduces. After several more doses of the ten kinds of formula, the white foam completely disappears and one can lie down very comfortably. Isn't this clear evidence that Prepared Rehmannia Root disperses phlegm? Prepared Rehmannia Root disperses phlegm without producing phlegm, so why doubt it? As for the stagnation of qi, taking Rehmannia Decoction disperses phlegm in an instant, so how can one say that qi is not moving? In life, as we eat and drink, the qi of the spleen and kidneys moves, and the food and water entering the abdomen do not turn into phlegm but into essence. Only when the spleen and kidneys are deficient does the food and water entering the abdomen not transform into essence but resolve into phlegm. Those who use Rehmannia Decoction to eliminate phlegm often find they can eat heartily, which shows that Prepared Rehmannia Root is a supreme product for opening the stomach. Why can it open the stomach? The stomach is the gate of the kidneys; when kidney water is abundant, the body fluids in the stomach naturally moisten, so when kidney qi is sufficient, stomach qi is also sufficient, and when kidney qi rises, stomach qi also rises. Therefore, Prepared Rehmannia Root moves qi rather than stagnating it, which is something we can all believe. When qi moves, phlegm disperses, how can it cause panting? This is especially something we need not doubt.

Someone asked, since Prepared Rehmannia Root is a sovereign medicinal, can it be used alone to achieve results? Although Prepared Rehmannia Root is a sovereign medicinal, it cannot be used alone to win. Yang medicines can be used singularly, but yin medicines must be used in pairs. Moreover, Prepared Rehmannia Root is a product of extreme yin, and its nature is very pure; without the assistance of more aggressive medicines, it definitely cannot succeed. This is why the Four Ingredients Decoction for tonifying blood must be supplemented with Chinese Angelica, Peony Root, and Sichuan Lovage Rhizome. Extending this, when used with Ginseng, it can tonify the heart and kidneys; with White Atractylodes Rhizome, it can tonify deficiencies in the spleen and kidneys; with Ophiopogon Tuber and five flavors, it can nourish the lungs and kidneys when they are drying up; with Peony Root, it can benefit the liver and kidneys when they are failing; with Cassia Bark, it can assist the declining fire of the life gate; with jujube seeds, it can calm the boiling fire in the chest; with Sanguisorba, it can clear the blood in the large intestine; with Coastal Glehnia Root, it can cool the inflammation in the stomach; with Scrophularia Root, it can purge the flames of Yangming. However, it must be used in amounts of one or two taels as the sovereign, with the assisting flavors added in amounts of five or eight qian, to easily achieve victory in Wan Quan. If Prepared Rehmannia Root is used in small amounts, its power is incomplete, so how can it win? Among these, only Cassia Bark should be used in one or two qian, not more than three qian, while the others can be used in large amounts with Prepared Rehmannia Root without concern.

Someone asked, must Prepared Rehmannia Root be used before childbirth to tonify blood, and can it also be heavily used after childbirth? It is said: It is especially appropriate to use it heavily after childbirth. The blood of a postpartum woman is greatly depleted; if Prepared Rehmannia Root is not used to generate new blood, what medicine should be used? Although Finger Citron Powder is a sacred medicine for postpartum, adding Prepared Rehmannia Root can make the generation of blood even more remarkable. For all postpartum dizziness due to hemorrhage and other diseases, using it together with Ginseng and Chinese Angelica will surely achieve remarkable results, not just for postpartum umbilical and abdominal pain. The original qi in the kidneys is the ancestor of postnatal life; Prepared Rehmannia Root is born from the qi of prenatal life. When a postpartum woman's blood chamber is depleted, the original qi is greatly consumed, and postnatal blood cannot be quickly generated, so it relies on prenatal qi to generate it. Using Prepared Rehmannia Root to assist postnatal life has a wonderful rationale, it's not just a general discussion.

Someone asked, does Prepared Rehmannia Root clog the diaphragm and produce phlegm, and can it be controlled with ginger juice and Villous Amomum Fruit? But Prepared Rehmannia Root does not clog the diaphragm. Prepared Rehmannia Root is sweet in taste and warm in nature; the sweet taste is favored by the spleen and stomach, and the warm nature is suitable for the spleen and stomach. Since the spleen and stomach do not conflict with it, why should it be feared to clog the diaphragm? Moreover, Prepared Rehmannia Root is a medicine of the yin aspect; it does not stay in the stomach but in the kidneys. The stomach is the gate of the kidneys; when the stomach encounters the flavor of the kidney channel, does it not guide it to the kidneys? The idea that it clogs the diaphragm comes from people who do not understand medical principles and should not confuse those who deeply understand medical principles. Although ginger juice opens the stomach and Villous Amomum Fruit revives the spleen, they do not hinder Prepared Rehmannia Root, but one should not say that Prepared Rehmannia Root clogs the diaphragm and produces phlegm.

Some say that Prepared Rehmannia Root is not greasy to the diaphragm, so why are Poria, Chinese Yam, and Alisma added to the Six-Ingredient Rehmannia Pill? Is it not because Prepared Rehmannia Root is greasy to the diaphragm that these are used? Thus, Poria, Chinese Yam, and Alisma are used to regulate Prepared Rehmannia Root, but how lightly are Poria, Chinese Yam, and Alisma regarded! The kidneys should be nourished and not purged. Since Prepared Rehmannia Root is used to nourish the kidneys, how can purgative herbs be used to purge the kidneys? Moreover, using purgative herbs to regulate the kidney-nourishing herb would result in purging without nourishing. Therefore, it is clear that Prepared Rehmannia Root should not be regulated. Since Prepared Rehmannia Root should not be regulated, the use of Poria, Chinese Yam, and Alisma is not for regulating Prepared Rehmannia Root, and this is also clear. Since Prepared Rehmannia Root should not be regulated, the use of Poria, Chinese Yam, and Alisma is not because Prepared Rehmannia Root is greasy to the diaphragm, and this is also clear. So, what is the purpose of using these three herbs? It is because Prepared Rehmannia Root can enrich yin but cannot remove dampness, and can nourish water but cannot generate yang. These three herbs are used to assist in achieving its purpose, not to hinder its effectiveness.

Someone asked: Since Prepared Rehmannia Root does not clog the diaphragm, why does it produce phlegm? Did the ancients speak without reason? I say: Prepared Rehmannia Root is actually a sacred medicine for dispersing phlegm, yet the world overlooks its efficacy. This is why I am determined to clarify it. The generation of phlegm originates from the deficiency of kidney qi, and the formation of phlegm is due to the weakness of stomach qi. If kidney qi is not deficient, then stomach qi will not be weak. If the kidney is not deficient, phlegm cannot be generated; if the stomach is not weak, phlegm cannot be formed. Therefore, to prevent the formation of phlegm, one must tonify the stomach, and to prevent the generation of phlegm, one must tonify the kidney. When kidney qi is sufficient and stomach qi is also sufficient, there will be no phlegm in the kidney or stomach. Although Prepared Rehmannia Root is a kidney-tonifying medicine, it is also a stomach-tonifying medicine. The body fluids in the stomach originate from the kidney. By tonifying the kidney to generate body fluids in the stomach, true water rises in the stomach. When true water rises in the stomach, the pathogenic fluids in the stomach naturally find it difficult to remain, and accumulated phlegm and saliva dissipate, achieving an effect that is both natural and miraculous. Is it not true that Prepared Rehmannia Root disperses phlegm? How can it be said to clog the diaphragm and produce phlegm?

Someone asked: Since Prepared Rehmannia Root tonifies the water in the kidney, why is it necessary to use Chinese Yam and Asiatic Cornelian Cherry Fruit as adjuvants? It is because kidney water cannot be generated without sourness. Asiatic Cornelian Cherry Fruit is sour in taste and warm in nature, and when combined with Prepared Rehmannia Root, it creates a harmonious blend like milk and water. However, Asiatic Cornelian Cherry Fruit is excessively sour, and without the sweet warmth of Prepared Rehmannia Root, it cannot alone generate kidney water. When combined appropriately, they work together like a harmonious couple, achieving the effect of mutual support.

Someone asked: Why is Prepared Rehmannia Root the sovereign herb in the Eight-Ingredient Rehmannia Pill? It is because the Eight-Ingredient Pill tonifies the fire in the kidney. However, fire cannot be tonified alone; it must be tonified within water. Since tonifying fire requires tonifying water, the herb that tonifies water must naturally be the sovereign. Among the herbs in the formula, only Prepared Rehmannia Root is the sacred medicine for tonifying water, so it is chosen as the sovereign. With a sovereign, there must be ministers, and Chinese Yam and Asiatic Cornelian Cherry Fruit serve as the ministers. With ministers, there must be assistants and messengers, and Moutan Bark, Alisma, and Poria serve in these roles. As for Cinnamon and Aconite, they are more like guests. Cinnamon and Aconite aim to tonify fire but cannot act independently, so they must defer to Prepared Rehmannia Root as the sovereign, tonifying water to tonify fire.

Someone asked: Can Prepared Rehmannia Root be used alone to treat diseases? Prepared Rehmannia Root can indeed be used alone. For diseases involving non-interaction between the heart and kidney, simply take two taels of Prepared Rehmannia Root, decoct it into a soup, and consume it on an empty stomach. The heart and kidney will harmonize in an instant. People think of Prepared Rehmannia Root as a kidney meridian herb, but who would have known it can also ascend to the heart? When the heart and kidney are dry, the kidney, nourished by water, sends its essence upward to the heart. The heart, nourished by the kidney, sends its qi downward to the kidney. Why bother with Coptis Rhizome and Cassia Bark?

Someone asked: Since Prepared Rehmannia Root can be used alone to achieve success, can it be used as a single herb in pill form for diseases of non-interaction between the heart and kidney, taken morning and evening? This, however, is not advisable. Using Prepared Rehmannia Root alone is only suitable for occasional, extraordinary cases. For long-term success, it must be assisted by Poria with Pine and Chinese Yam, and supported by Asiatic Cornelian Cherry Fruit and Ziziphus Seed.

Someone asked: Should Prepared Rehmannia Root be used in large doses to achieve results, or in small doses to be effective? Prepared Rehmannia Root should be used in large doses rather than small ones. However, when used appropriately, even a large dose of several taels does not seem excessive; when used inappropriately, even a small dose of a few qian may seem insufficient. When used during severe kidney water deficiency, a large dose may still feel insufficient; when used during severe spleen earth collapse, even a small dose may feel excessive; when used for kidney fire hyperactivity, a large dose may still fall short; when used for stomach earth abscesses, even a small dose may feel too much. The key lies in using it appropriately, and the amount, whether large or small, should not be overly calculated.

Some suspect that Prepared Rehmannia Root is cloying and that excessive tonification of yin may cause obstruction, making it unsuitable for single use to achieve success. Yet, why have some ancients succeeded in using it alone? I say: Using Prepared Rehmannia Root alone for extraordinary effects is a temporary expedient. It is better to combine it with other herbs to achieve greater success. For example, for heart and kidney deficiency, add Longan Aril; for liver and kidney deficiency, add Peony Root; for lung and kidney deficiency, add Ophiopogon Tuber; for spleen and kidney deficiency, add Ginseng or Peony Root. This way, there is no cloying of the diaphragm, and the effects are more rapid. It all depends on the practitioner's adaptability.

Some may doubt that for those with kidney deficiency, Prepared Rehmannia Root should be used to tonify yin, but why is it also used to tonify the stomach and the gallbladder? This is indeed an expedient method of the ancients, but it is also a very appropriate method. The stomach is the gate of the kidneys; kidney deficiency leads to stomach deficiency, and tonifying the kidneys is precisely how to tonify the stomach. Although the gallbladder is attached to the liver, the bile must be infused with the fluid of the kidneys to avoid the risk of drying up. Kidney deficiency leads to gallbladder deficiency, and tonifying the kidneys is precisely how to tonify the gallbladder. If one sees stomach deficiency and only uses stomach-tonifying medicines, the fragrant and drying substances will further deplete the kidney water. If one sees gallbladder deficiency and only uses gallbladder-tonifying substances, the sour and astringent agents will further exhaust the kidney water. If the kidneys are already deficient, the stomach and gallbladder will become even weaker. Only by using Prepared Rehmannia Root to tonify the kidneys can the stomach and gallbladder draw from the kidneys and have more than enough, naturally preventing dryness and withering. Who says that yang conditions are not suitable for tonifying yin?

Some may doubt that Prepared Rehmannia Root, being a medicine of extreme yin, is often used to nourish the kidneys. However, why did ancient people also use it to treat diseases of extreme yang and achieve results? Could it be that Prepared Rehmannia Root is also a yang medicine? Prepared Rehmannia Root is not a yang medicine. Although it is not a yang medicine, it is specifically used to treat yang diseases because yang is balanced by yin. Yang cannot be subdued without yin. Using Prepared Rehmannia Root to capture the qi of extreme yang results in the rising of water and the descending of fire, achieving the harmony of yin and yang.

Some may doubt that Prepared Rehmannia Root enriches yin but cannot stimulate the stomach. However, it is actually a miraculous medicine for opening the stomach. The stomach is the gateway to the kidneys. When the kidneys are depleted, they rely entirely on the stomach's gateway to transport water and grains to alleviate their deficiency. How could the stomach reject what the kidneys favor? Moreover, when there is kidney deficiency and lack of water, the stomach is filled with fire qi and urgently needs true yin water to relieve its dryness. Therefore, Prepared Rehmannia Root is favored not only by the kidneys but also by the stomach. How could the stomach not open its gates to welcome what it favors? Thus, people with kidney deficiency must use Prepared Rehmannia Root to stimulate the stomach. However, if the kidney water is not deficient and there is no fire in the stomach, using Prepared Rehmannia Root suddenly may cause slight bloating and discomfort, which is due to improper use of the herb. Who says Prepared Rehmannia Root is entirely a stomach-closing substance?

Bencao Fenjing : Sweet, slightly warm. Enters the three yin meridians of the foot. Nourishes the kidneys and liver, fills the marrow, also supplements spleen yin, benefits the blood vessels, enhances true yin, eliminates phlegm, reduces fever, and stops diarrhea. Treats all liver and kidney yin deficiencies, as well as various deficiency-related illnesses. It is the primary medicine for strengthening water. When combined with powder, it can also induce sweating, and when combined with warm agents, it can restore yang. Note: Prepared Rehmannia Root should be steamed and sun-dried nine times. Multiple steamings prevent stagnation, and multiple sun-dryings warm the qi, embodying the principle of yang arising from water. If it is used after only one steaming and without sun exposure, how is it different from using Unprocessed Rehmannia Root in decoction?

Yixue Zhongzhong Canxilu : Fresh Rehmannia: Cold in nature, slightly bitter and slightly sweet. Best at clearing heat, cooling blood, transforming static blood, and generating new blood. Treats reckless blood flow due to heat, hematemesis, nosebleeds, and bloody stools caused by heat. It contains iron, which turns black when sun-dried or steamed, and its blood-generating and cooling abilities are also attributed to its iron content.

Dried Rehmannia (i.e., Unprocessed Rehmannia Root in pharmacies): Sun-dried, cool but not cold in nature, generates blood vessels, enriches essence, sharpens the senses, treats steaming bone fever, and heat generated by kidney deficiency.

Prepared Rehmannia Root (made from fresh Rehmannia and wine, repeatedly steamed and sun-dried): Slightly warm in nature, sweet but not bitter, it is the primary medicine for enriching yin and nourishing the kidneys. Treats yin-deficiency fever, yin deficiency causing breathlessness and wheezing, pulmonary tuberculosis cough, kidney deficiency leading to water retention, scanty urine, and resulting edema, as well as yin deficiency in all zang-fu organs. Prepared Rehmannia Root can nourish all these conditions.

bubble_chart Modern Pharmacology

1. Prepared Rehmannia Root not only improves yin deficiency symptoms through systemic regulation but also adjusts abnormal thyroid hormone states.
2. Prepared Rehmannia Root can improve AD levels in the body, aiding in enriching yin and nourishing the kidneys.
3. Prepared Rehmannia Root can increase the activity of SOD and DGSH-PX in the blood of mice, reduce IPO content, and to varying degrees, decrease the rate of protein decomposition in liver and kidney tissues while increasing the rate of protein synthesis in lung tissues.
4. Prepared Rehmannia Root can activate the solution system's activity and significantly counteract the occurrence of DIC in rats induced by thrombin and internal toxins.
5. The ether-soluble substances in Prepared Rehmannia Root can reduce peripheral T lymphocytes in mice by 14%, but have no significant effect on other immune functions.
6. Extracts of Prepared Rehmannia Root have a certain inhibitory effect on the mitosis of epithelial cells.