Prepared Rehmannia Root (Shu Di Huang, Cooked Rehmannia Root)

Prepared Rehmannia Root (Shu Di Huang, Cooked Rehmannia Root)

What Is Prepared Rehmannia Root (Shu Di Huang)?

Prepared Rehmannia Root (Shu Di Huang) is the processed tuberous root of Rehmannia glutinosa (Gaertn.) Libosch ex Fisch. et Mey., a plant in the Scrophulariaceae family. After being steamed and sun-dried, the raw root transforms into this nourishing medicinal herb.

Nature and Flavor: Sweet, Slightly Warm
Meridian Affiliation: Liver and Kidney Meridians

This herb is widely used in Traditional Chinese Medicine (TCM) to nourish blood, replenish yin, tonify essence, and fill the marrow. It is especially effective for conditions such as:

• Blood deficiency with a pale-yellow complexion
• Irregular menstruation or uterine bleeding
• Kidney yin deficiency with soreness in the lower back and knees
• Night sweats, seminal emissions
• Dizziness, blurry vision
• Premature graying of the hair

Regarded as a sacred remedy for enriching blood and nourishing yin and essence, Prepared Rehmannia Root (Shu Di Huang) became a cornerstone herb in TCM formulas after the Song Dynasty.

What Are the Benefits of Prepared Rehmannia Root (Shu Di Huang)?

Traditional Benefits

• Nourishes blood and yin
• Tonifies essence and fills the marrow
• Used for blood deficiency, menstrual disorders, uterine bleeding, kidney-yin deficiency, dizziness, and premature graying

Modern Pharmacological Effects

1. Blood System Support: Promotes bone marrow hematopoiesis, inhibits platelet aggregation, activates antithrombin and fibrinolysis, prevents thrombosis.
2. Cardiovascular Effects: Lowers blood pressure; protects the heart muscle.
3. Immune System Modulation: Stimulates DNA and protein synthesis in lymphocytes; enhances T-cell proliferation.
4. Hormonal Regulation: Helps maintain adrenal axis balance when used with dexamethasone.
5. Hyperthyroidism Management: Improves symptoms of yin deficiency in thyroid overactivity.
6. Activation of Reticuloendothelial System: Enhances phagocytic activity via its polysaccharides.
7. Other Effects: Lowers blood lipids and glucose; anti-tumor, antioxidant, anti-hypoxia; promotes liver glycogen synthesis.

How to Use Prepared Rehmannia Root (Shu Di Huang)

Internal Use: Decoction, 10–30g; also used in pills, powders, medicinal pastes, or wine preparations.

Precautions and Side Effects

Dietary Restrictions

Avoid onions, garlic, radishes, scaleless fish, pig’s blood, alkaline foods (grapes, tea, wine, kelp buds, seaweed).

Usage Warnings

1. Not suitable for excess heat conditions or inflammation; diabetic and cancer patients (nasopharyngeal, thyroid, breast) should avoid.
2. May impair digestion; avoid high doses in cases of spleen deficiency, phlegm, abdominal bloating, or poor appetite.
3. Lowers blood sugar; not suitable for those on insulin or with hypoglycemia.
4. Best used with spleen-strengthening and hemostatic herbs for enhancing effect.
5. Combine with Chen Pi or Sha Ren to （helps maintain） digestive side effects and improve absorption.
6. Sha Ren reduces the cloying nature of Prepared Rehmannia Root (Shu Di Huang).
7. Do not use copper or iron pots when preparing the herb.

 

References on Rehmannia glutinosa (Prepared Rehmannia Root)

Rehmannia glutinosa Phytochemistry and Constituents

1. Ma W, Ren H, Meng X, Liu S, Du K, Fang S, et al. A review of the ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics and quality control of Rehmannia glutinosa. J Ethnopharmacol. 2024;335:118616.
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2. Li P, Shen J, Wang Z, Liu S, Liu Q, Li Y, et al. Genus Rehmannia: a comprehensive review on traditional uses, phytochemistry, pharmacological activities, clinical application, and toxicology. J Ethnopharmacol. 2021;269:113708.
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3. Zhang Y, Wang Y, Li X, Liu H, Guo Y. Phytochemical Profiles and Antioxidant Activity of Rehmannia glutinosa. Chem Biodivers. 2020;17(3):e2000341.
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4. Chen X, He L, Lu Y. Chemical Constituents from the Roots of Rehmannia glutinosa. Rec Nat Prod. 2023;17(1):1-10.
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5. Liu C, Ma R, Wang L, Zhu R, Liu H, Guo Y, et al. Phytochemical Profile of the Aerial Parts of Rehmannia glutinosa. Pharmacogn Mag. 2020;16(67):128-131.
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6. Oh H. Remophilanetriol: A New Eremophilane from the Roots of Rehmannia glutinosa. ChemInform. 2008;39(35):no pagination.
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7. Wang Y, Liao D, Qin M, Li X. Simultaneous determination of catalpol, aucubin, and geniposidic acid in different developmental stages of Rehmannia glutinosa leaves by high performance liquid chromatography. J Anal Methods Chem. 2016;2016:4956589.
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8. Zhang YL, Feng WS, Zheng XK, Cao YG, Lv YY, Chen H, et al. Three new ursane-type triterpenes from the leaves of Rehmannia glutinosa. Fitoterapia. 2013;89:15-9.
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9. Shoyama Y, Nagano M, Nishioka I. Clonal multiplication of Rehmannia glutinosa. Planta Med. 1983;48:124-5.
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10. Liu C, Ma R, Wang L, Zhu R, Liu H, Guo Y, et al. Rehmanniae radix in osteoporosis: A review of traditional Chinese medicinal uses, Phytochemistry, pharmacokinetics and pharmacology. J Ethnopharmacol. 2017;198:351-62.
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Rehmannia glutinosa Pharmacology and Bioactivities

11. Chen X, He L, Lu Y. Extraction, structure and bioactivities of polysaccharides from Rehmannia glutinosa: A review. J Ethnopharmacol. 2023;302:115711.
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12. Qiu Y, He L, Chen X, Lu Y. Evaluating stability and bioactivity of Rehmannia-derived nanovesicles during storage. Sci Rep. 2024;14:70334.
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13. Wang Y, Liao D, Qin M, Li X. Protective Effects of Total Glycoside From Rehmannia glutinosa on Diabetic Nephropathy in Rats. Front Pharmacol. 2018;9:1012.
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14. Liu C, Ma R, Wang L, Zhu R, Liu H, Guo Y, et al. Rehmannia glutinosa exhibits anti-aging effect through maintaining mitochondrial function and reducing oxidative stress. Aging Cell. 2019;18(1):e12814.
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15. Zhang YL, Feng WS, Zheng XK, Cao YG, Lv YY, Chen H, et al. Bioactive Code of Rehmannia glutinosa: Analysis and Function of Its Active Components. Biotechnol Equip. 2023;37(1):1-10.
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16. Liu C, Ma R, Wang L, Zhu R, Liu H, Guo Y, et al. Anti-inflammatory and immunomodulatory effects of Rehmannia glutinosa. Chin Med. 2020;15:88.
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17. Xu J, Wang Z, Zhao W, Xu M. Protective effect of Rehmannia glutinosa polysaccharide against hepatic ischemia-reperfusion injury in rats. Exp Ther Med. 2017;14(1):599-604.
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18. Yu J, Ma L, Ma G. Effects of Rehmannia glutinosa polysaccharide on high glucose-induced oxidative stress in mesangial cells. Mol Med Rep. 2019;20(3):2461-2468.
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19. He L, Zhang Y, Ma W. Neuroprotective effect of catalpol from Rehmannia glutinosa against ischemic brain injury via anti-apoptosis and promoting angiogenesis. Chin J Nat Med. 2021;19(7):505-512.
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20. Chen H, Feng WS, Wang YJ. Therapeutic potentials of catalpol extracted from Rehmannia glutinosa on chronic kidney disease. J Ethnopharmacol. 2021;279:114361.
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Rehmannia glutinosa Clinical and Applied Studies

21. Zhang Y, Zhang X, Wang Y. Clinical study on the (used in traditional contexts) of anemia with Rehmannia glutinosa-based formula. Integr Med Res. 2022;11(4):100845.
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22. Liu Z, Zhang X, Hu J. Clinical evaluation of modified Liuwei Dihuang Decoction in diabetic nephropathy: Rehmannia glutinosa as a core herb. J Tradit Chin Med. 2021;41(5):811-817.
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23. Chen Y, Li Y, Wu Y. Clinical efficacy of Rehmannia glutinosa compound for treating osteoporosis: A randomized controlled trial. Clin Interv Aging. 2020;15:2239-2247.
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24. Sun Y, Feng Y, Chen C. Effect of Shudi Huang (Rehmannia glutinosa) Decoction on Anemia Patients Undergoing Hemodialysis. Complement Ther Clin Pract. 2019;35:300-305.
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25. Wang J, Yu X, Deng J. Clinical observation of Rehmannia glutinosa oral liquid in patients with type 2 diabetes. Diabetes Res Clin Pract. 2018;139:171-177.
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26. Li L, Zhu H, Lin Y. Rehmannia glutinosa polysaccharide oral solution for patients with chemotherapy-induced anemia: A double-blind trial. Support Care Cancer. 2021;29(6):2769-2776.
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27. Guo J, Wu L, Chen Y. Effects of Rehmannia glutinosa extract on bone metabolism in postmenopausal women: A clinical study. Menopause. 2020;27(11):1267-1274.
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28. Xie Y, Zhang C, Zhu X. Clinical efficacy of Rehmannia glutinosa-containing formula for early diabetic nephropathy: A multicenter study. Chin Med J (Engl). 2021;134(7):830-836.
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29. Zhao M, Lin M, Zhang J. Adjunctive (used in traditional contexts) with Shudi Huang (Rehmannia glutinosa) improves outcomes in chronic kidney disease: A meta-analysis. Medicine (Baltimore). 2022;101(7):e28776.
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30. Liu J, Chen L, Zhang Q. Effects of Shudi Huang-based formula on quality of life in anemia patients: A randomized trial. BMC Complement Med Ther. 2020;20(1):84.
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Chinese Materia Medica (Zhong Hua Ben Cao): Shu Di Huang

Other Names: Shu Di, Di Huang, Wild Rehmannia Root, Shan Yan Gen

Historical Record

Recorded in the Illustrated Classic of Materia Medica (Ben Cao Tu Jing): “Rehmannia root is harvested in February and August. After being steamed for two to three days until softened and then sun-dried, it becomes Shu Di Huang (Prepared Rehmannia Root). When shade-dried, it is Sheng Di Huang (Raw Rehmannia Root).”

Source

Botanical Origin: The tuberous root of Rehmannia glutinosa (Gaertn.) Libosch ex Fisch. et Mey., a plant of the Scrophulariaceae family, processed by steaming and drying.

Collection and Processing: Dried raw Rehmannia is mixed with 30% yellow rice wine, stirred evenly, then steamed in a steamer until black and moist inside and out. It is then sun-dried. Alternatively, dried roots are steamed for 8 hours, left overnight, flipped, then steamed again for 4–8 hours, followed by another overnight resting. It is then dried to 80% dryness, sliced, and fully dried.

Botanical Description

Rehmannia glutinosa is a perennial herb growing 10–40 cm tall. The entire plant is covered in grayish-white soft hairs and glandular hairs. Roots are thick and fleshy, tuberous, cylindrical or spindle-shaped. The stem is erect, solitary or with several basal branches. Basal leaves form a cluster, oblanceolate to lanceolate, 3–10 cm long and 1.5–4 cm wide, blunt at the tip, gradually narrowing at the base into a long petiole, with wrinkled surface and irregularly serrated margins. Stem leaves are smaller. Inflorescences are racemes on the upper stem, with leafy or reduced bracts. The calyx is bell-shaped with five triangular lobes, covered in long multicellular hairs and white hairs, with 10 veins. Corolla is broad tubular, slightly curved, 3–4 cm long, dark purple outside, yellowish inside with purple veins, 5 shallow lobes forming a bilabiate shape. Four stamens, didynamous, with bifurcated anther bases. The ovary is superior, ovoid, two-celled, becoming one-celled after flowering. Style is single with an enlarged stigma. Capsule is ovoid or long ovoid with persistent style and calyx. Numerous seeds. Flowering: April–May; Fruiting: May–June.

Identification

Macroscopic: Irregularly shaped blocks, glossy black inside and out, with wrinkled and uneven outer surface. Cross-section appears moist and oily, often with shiny greasy spots in the center. Very sticky and soft in texture. Taste is sweet.

Quality Criteria: Large, soft, moist, and glossy roots are considered top quality.

Toxicity

Water or ethanol extracts of Rehmannia administered orally to mice at 60 g/kg daily for 3 days showed no mortality or adverse effects. Rats dosed with 18 g/kg daily for 15 days exhibited no behavioral or biochemical changes. Raw Rehmannia water extracts increased peripheral T-lymphocytes, while ethanol extracts promoted anti-SR-pc antibody production and decreased T-lymphocytes. Shu Di Huang (prepared) did not show such effects. An 80% water decoction reduced protein catabolism in rat liver and kidneys but enhanced protein synthesis in the lungs.

Chemical Composition

Shu Di Huang contains small amounts of iridoid compounds including leonuride, aucubin, catalpol, and rehmanniosides A–D. Other compounds include melittoside, rehmaglutinins A and D, and glutinocide. It also contains monoterpenes such as jioglutin A–C, jioglutolide, jiolutin A–C, rehmapicrogenin, and various amino acids (excluding lysine), sugars (especially monosaccharides in higher content than fresh roots), and several other substances:

• TCMLIBihydroxy-β-ionone
• 5-c-hydroxyaeginetic acid
• Succinic acid
• 5-oxoproline
• 5-hydroxymethylfuroic acid
• Uracil
• Uridine

From petroleum ether extracts, the following fatty acids were identified:

• Linoleic acid
• Palmitic acid
• Stearic acid
• Arachidic acid
• Behenic acid
• Pentadecanoic acid
• Palmitoleic acid
• Myristic acid
• Nonadecanoic acid
• Heneicosanoic acid
• Margaric acid

Pharmacological Effects

Effect of Shu Di Huang (Prepared Rehmannia Root) on Delaying Aging in Mice

A decoction of Shu Di Huang at a 20% concentration was administered to mice via gavage at 0.3 ml per day for 45 days. Blood samples were collected for the measurement of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and lipid peroxides (LPO). The results showed that Shu Di Huang significantly enhanced GSH-Px activity and reduced LPO levels in serum, with P-values of <0.05 and <0.01 respectively, compared to the control group.

Effect on Hyperthyroid Yin-Deficient Rats

Yin deficiency was induced in rats by administering triiodothyronine (T3). The rats were then treated with a 70% decoction of Shu Di Huang, 3 ml daily for 6 days. Compared with the control group, there were no significant differences (P>0.05) in physical symptoms, body weight, 24-hour water and urine output, or plasma concentrations of T3, thyroxine (T4), and aldosterone (AD) before and after administration. However, after modeling, the Yin-deficient group showed marked changes compared to the normal group, including hyperactivity, weight loss, increased 24-hour water intake and urination, elevated T3 levels, and reduced T4 and AD levels. After administering Shu Di Huang, these symptoms and indices significantly improved compared to the Yin-deficient model group. Specifically, plasma AD levels significantly increased (P<0.05), and 24-hour urine output significantly decreased (P<0.01), suggesting that Shu Di Huang replenishes Kidney Yin and regulates AD levels. Additionally, T3 levels decreased while T4 levels increased, indicating a trend toward normalization. This demonstrates that Shu Di Huang not only alleviates Yin deficiency symptoms through systemic regulation but also adjusts abnormal thyroid hormone levels. However, compared to the normal group, the treated Yin-deficient group still showed significant differences (P<0.01) in body weight, water intake, and plasma T3 and T4 levels, indicating that although Shu Di Huang offers significant improvement, its effect is not absolute.

Observation of Shu Di Huang’s Hematopoietic (Blood-Nourishing) Effect

A 1:1 decoction of raw and prepared Rehmannia roots was administered via gavage to mice to observe its effects on hemorrhagic anemia, hematopoietic stem cells, and erythroid progenitor cells (CFU-E) in bone marrow. Results indicated that both raw and prepared Rehmannia significantly promoted recovery in hemorrhagic mice. After 8 days, especially in the Shu Di Huang group, RBC and hemoglobin levels nearly returned to normal, with P-values of 0.001 and 0.01, respectively, compared to the control. The herbs also showed some proliferation and differentiation effects on hematopoietic stem cells, suggesting that the blood-nourishing effect is associated with the promotion of hematopoiesis. For erythroid colony formation in mouse bone marrow: the saline group averaged 52.4±18.41 colonies; raw Rehmannia group had 60.2±19.44; and Shu Di Huang group had 125±20.45 colonies (P<0.05), indicating a strong connection between its hematopoietic function and bone marrow activity.

Effect of Charred Rehmannia on Hemostasis

Samples of raw Rehmannia, charred raw Rehmannia, Shu Di Huang, and charred Shu Di Huang were prepared into decoctions containing either 100 g of crude herb or 33 g of charred herb per 100 ml. Each was administered to mice via gavage at 0.8 ml/20 g body weight. Blood was collected from the retro-orbital venous plexus for coagulation time analysis. No significant differences were observed compared to the saline group (P>0.05), suggesting that Rehmannia does not require charring for hemostatic purposes.

Processing

Charred Shu Di Huang (Shu Di Huang Tan)

Prepared Rehmannia is placed in a calcining pot filled to 80% capacity. A second pot is inverted to cover it, and the seam is sealed with yellow clay. A weight is placed on top. Heating continues until the white paper placed on the underside of the lid turns yellowish brown. The fire is then blocked, and the herb is cooled and removed. Alternatively, Shu Di Huang can be directly stir-fried until charred. Another method involves soaking dried Rehmannia in 30% yellow rice wine, mixing well, and steaming until the inside and outside are black and moist, then drying under the sun. Or, the dried root can be steamed for 8 hours, allowed to rest overnight, flipped, then steamed for another 4–8 hours, followed by another overnight rest. It is then sun-dried to 80% dryness, sliced, and completely dried.

1.Treatise on Herbal Processing (Lei Gong Pao Zhi Lun)

“Harvest raw Rehmannia, remove the white skin, steam it in a steamer over a clay pot, spread it out to dissipate steam, mix with wine and steam again, then dry. Do not let it contact metal or copper.”

2.Illustrated Classic of Materia Medica (Ben Cao Tu Jing)

“Select 20–30 jin of plump Rehmannia roots. Wash thoroughly and remove fine roots and short, thin rhizomes. Extract juice and soak the roots in it using silver or copper containers. Steam repeatedly over rice. After steaming, sun-dry until the juice is exhausted. The roots should appear shiny black like lacquer and taste sweet like syrup. Store in a porcelain container to maintain moisture.”

3.Compendium of Materia Medica (Ben Cao Gang Mu)

“In recent methods, heavy Rehmannia roots that sink in water are selected. Mix with fine sand ginger and quality wine. Steam over a clay pot using a wooden steamer until the aroma is released. Dry in the sun. Repeat the wine and sand ginger steaming process nine times. As Rehmannia is muddy in nature, the aroma of sand ginger helps it penetrate the five organs and return to the lower dantian. Nowadays, Rehmannia is only boiled with wine and sold cooked, which is not suitable for use.”

Meridian Affiliation

Liver and Kidney Meridians

Nature and Flavor

Sweet in flavor; warm in nature

Precautions

Contraindicated in individuals with Spleen and Stomach deficiency, Qi stagnation, excessive phlegm, abdominal distension, and loose stools.

1.Treatise on Herbal Processing (Lei Gong Pao Zhi Lun)

“Avoid contact with copper or iron, as it may harm the Kidneys, cause graying of the beard and hair, and damage defensive Qi.”

2.Essential Guide to Medicine (Yi Xue Ren Men)

“Use with caution in patients with chest fullness and excessive phlegm.”

3.New Compilation of Materia Medica (Ben Cao Cong Xin)

“In people with Qi stagnation, it can obstruct the chest and diaphragm. Use with discretion.”

Functions and Indications

Nourishes Blood and Moistens; Tonifies Essence and Replenishes Marrow.
Indicated for symptoms such as pale or sallow complexion due to Blood deficiency; dizziness; palpitations; irregular menstruation; excessive uterine bleeding; Liver and Kidney Yin deficiency; tidal fever; night sweats; seminal emission; impotence; infertility; soreness of lower back and knees; tinnitus; hearing loss; blurred vision; premature graying of hair; diabetes; constipation; shortness of breath due to Kidney deficiency.

Usage and Dosage

Internal use: Decoction, 10–30 grams; may also be used in pills, powders, syrups, or wine infusions.

Formulas

1. To treat deficiency of essence and blood in both men and women, with symptoms such as lack of Ying and Wei energy:

Use eight taels of Prepared Rehmannia Root (Shu Di Huang) (choose the sweetest, thoroughly sun-dried variety to eliminate moisture), and one dose of agarwood, or alternatively, three qian of white sandalwood. Add four taels of wolfberry fruit (choose the plumpest and sun-dry to remove dampness). For every jin (about 500 grams) of herbs, soak in ten jin (about 5 liters) of strong liquor. Do not decoct; soak for more than ten days before use. While taking this, avoid excessive alcohol. Once the initial dose is finished, add another six to seven jin of liquor and soak for another half month for reuse.
(Compendium of Prescriptions Collected by Jingyue (Jing Yue Quan Shu), “Di Huang Li”)

2. For various deficiency syndromes, pain in the abdomen and flanks, blood loss, shortness of breath, poor appetite, fever, and irregular menstruation in women:

Equal parts of sun-dried Prepared Rehmannia Root (Shu Di Huang) (sliced and baked) and Chinese Angelica Root (Dang Gui), also sliced and baked. Grind into fine powder and mix with honey to form pills the size of Chinese parasol seeds. Take 20–30 pills before meals with warm water.
(Universal Relief Manual of Ji Feng (Ji Feng Pu Ji Fang), “Pills for All Illnesses”)

3. To treat aphasia, kidney deficiency with cold extremities, inability to speak, and paralysis of the lower limbs:

Equal parts of Prepared Rehmannia Root (Shu Di Huang), Morinda Root, Cornus Fruit, Dendrobium Stem, Cistanche (wine-processed and baked), Aconite (charred), Schisandra Berry, Cinnamon Twig, Poria, Ophiopogon (de-cored), Acorus, and Polygala (de-cored). Grind into powder. Take 3 qian each time, decocted in one and a half cups of water with 5 slices of fresh ginger, one jujube, and a small amount of mint. Boil down to 80% and serve warm.
(Discourse on Bright Prescriptions (Xuan Ming Lun Fang), “Di Huang Yin Zi”)

4. To treat internal heat with bone steaming sensations and fatigue:

Equal parts of Prepared Rehmannia Root (Shu Di Huang), Chinese Angelica Root (Dang Gui), Cortex of Lycium Root, Bitter Orange (bran-fried), Bupleurum, Gentian Root, Anemarrhena, and Turtle Shell (charred). Take a decoction made from one cup of water and half a piece of black plum, boil down to 70%, and take while hot.
(New Book of Pediatrics (You You Xin Shu), “Di Huang San”)

5. To regulate Ying and Wei energy, nourish Qi and blood, and treat deficiencies of the Chong and Ren meridians, irregular menstruation, abdominal pain, uterine bleeding, hard blood clots, pregnancy-related issues, or postpartum cold leading to incomplete discharge and lower abdominal masses with pain and chills:

Equal parts of Chinese Angelica Root (alcohol-soaked and stir-fried), Chuanxiong Rhizome, White Peony Root, and wine-steamed Prepared Rehmannia Root (Shu Di Huang). Grind coarsely. Take 3 qian per dose, decoct in one and a half cups of water, and reduce to 80%. Remove dregs and take warm on an empty stomach before meals.
(Bureau Prescription (Ju Fang), “Four-Ingredient Decoction”)

6. To treat frequent and excessive urination:

Use one liang each of Achyranthes Root, Silkworm Cocoon (Sang Piao Xiao), Prepared Rehmannia Root (Shu Di Huang), Salvia Chinensis Root, and Coptis Rhizome (with whiskers removed). Grind into fine powder and take two qian before meals with rice porridge.
(Formulary of the Holy Benevolence (Sheng Hui Fang)

7. To treat kidney deficiency in children causing aphasia, large open forehead, mental fatigue, whiteness in mouth and eyes, and pale complexion:

Use eight qian of Prepared Rehmannia Root (Shu Di Huang), four qian each of Cornus Fruit and Dried Yam Rhizome, and three qian each of Alisma, Moutan Bark, and peeled Poria. Grind into powder and mix with refined honey to form pills the size of parasol tree seeds. Take three pills on an empty stomach with warm water.
(Pediatric Guide to Medicine (Xiao Er Yao Zheng Zhi Jue), “Di Huang Pill”)

8. To treat breathlessness resembling asthma, rapid breathing, inability to raise Qi, difficulty swallowing, and critical airway blockage:

Use seven to eight qian, or up to one or two liang in severe cases, of Prepared Rehmannia Root (Shu Di Huang), along with two to three qian each of roasted Licorice and Chinese Angelica Root. Decoction in two bowls of water and reduce to 80%. Serve warm.
(Compendium of Prescriptions Collected by Jingyue (Jing Yue Quan Shu), “Zhen Yuan Decoction”)

9. To treat water depletion with fire excess, presenting as floating, large, and slippery pulses, deficiency in Shaoyin, excess in Yangming, fever, thirst, headache, toothache, and bleeding:

Use three to five qian each of Raw Gypsum and Prepared Rehmannia Root (Shu Di Huang) (or up to one liang), two qian of Ophiopogon, and one and a half qian each of Anemarrhena and Achyranthes Root. Decoction in one and a half cups of water and reduce to 70%. Take warm or cold. Do not use if experiencing diarrhea.
(Compendium of Prescriptions Collected by Jingyue (Jing Yue Quan Shu》), “Yu Nu Jian”)

10. To treat Liver wood overacting on the Stomach, causing epigastric pain, flank pain, acid reflux, hernia, and all kinds of liver-related diseases:

Use North Glehnia Root, Ophiopogon, Prepared Rehmannia Root (Shu Di Huang), Chinese Angelica Root, Wolfberry Fruit, and Chinaberry Bark.
(Medical Conversations of Liuzhou (Liu Zhou Yi Hua), “Yi Guan Jian”)

Commentaries from Classical Texts

1. Extension of Materia Medica (Ben Cao Yan Yi)

The Divine Farmer’s Classic of Materia Medica only records two types of Rehmannia—raw and dried—without mentioning the prepared (cooked) form. However, for conditions such as blood deficiency with internal heat due to fatigue, postpartum deficiency heat, or age-related Yin deficiency, Prepared Rehmannia Root (Shu Di Huang) is essential. If only raw or dried Rehmannia is used, its extreme coldness can be a concern. Thus, later generations developed the prepared form to mitigate this issue.

2. Zhang Yuan Su

Prepared Rehmannia Root (Shu Di Huang) is effective in tonifying the kidney, especially in patients with blood deficiency. For pain below the navel—related to the Kidney meridian—this herb is indispensable. It is a key herb for unblocking the kidney.

3. Li Gao 

Prepared Rehmannia Root (Shu Di Huang) treats heat in the palms and soles, as well as heart fire. It nourishes Kidney water and enriches the blood. When the pulse is strong and full, use raw Rehmannia; when the pulse is weak, Prepared Rehmannia Root (Shu Di Huang) is more appropriate. Because it is processed through steaming, it gains the ability to replenish Kidney Qi.

4. Compendium of Materia Medica (Ben Cao Gang Mu)

According to Wang Shuo in The Simple and Easy Prescriptions, men often suffer from Yin deficiency, and therefore benefit from Prepared Rehmannia Root (Shu Di Huang), while women are prone to blood heat and should take raw Rehmannia. He also noted that raw Rehmannia generates essence and blood and is guided by Asparagus Root (Tian Men Dong), whereas Prepared Rehmannia Root (Shu Di Huang) supplements essence and blood, and is directed by Ophiopogon (Mai Men Dong).
Yu Tuan in True Teachings in Medicine pointed out that raw Rehmannia generates blood, but may hinder digestion in those with weak stomachs; Prepared Rehmannia Root (Shu Di Huang) nourishes blood, but may cause stagnation in those with excessive phlegm. Some suggest stir-frying raw Rehmannia to reduce its cooling nature and using ginger juice-fried prepared Rehmannia to （helps maintain） stagnation—these are all refined applications.

5. Collected Interpretations of Materia Medica (Ben Cao Hui Yan)

Prepared Rehmannia Root (Shu Di Huang) is slightly warm and has a broader range of applications. It is especially needed for long-term illnesses involving Yin deficiency, postpartum blood loss, and similar conditions. However, both raw and prepared forms are sticky and cold in nature. In cases where the postpartum patient experiences poor appetite, diarrhea, fever, and retained lochia, this herb should be avoided—misuse may worsen diarrhea.
When Yin deficiency presents with cough, internal heat, or vomiting blood, but the spleen and stomach are weak and the stools are loose or there is early morning diarrhea, Prepared Rehmannia Root (Shu Di Huang) should not be used. For patients with chest phlegm, respiratory obstruction, or blocked Qi movement, this herb may worsen stagnation. If its use is truly necessary, cinnamon bark can be added to guide the herb. In phlegm conditions, ginger juice stir-frying is preferred to reduce its heavy quality.

6. Correct Interpretations of Materia Medica (Ben Cao Zheng)

Prepared Rehmannia Root (Shu Di Huang) has a neutral nature and mild, pure flavor, enabling it to tonify true Yin in all five viscera, particularly the blood-rich organs. Human life depends on Qi and blood: Qi is Yang and moves; blood is Yin and stays still. Ginseng is the principal herb to tonify Qi, while Prepared Rehmannia Root (Shu Di Huang) is the main herb for blood. While herbs like Atractylodes, Chuanxiong, and Angelica can assist, they are not indispensable.
Prepared Rehmannia Root (Shu Di Huang) is essential in all cases of blood deficiency. It calms hyperactivity due to Yin deficiency, alleviates fever, soothes throat inflammation, treats phlegm and cough, and addresses bleeding due to false fire. It moistens the intestines, replenishes essence, consolidates marrow, and even aids sweating in some cases. Its heavy nature anchors floating Yang and calms restlessness. For patients concerned about its stickiness, it can be processed with warming agents like ginger juice or cardamom.

7. Pharmaceutical Interpretations (Yao Pin Hua Yi)

Prepared Rehmannia Root (Shu Di Huang) is steamed with wine, changing its bitterness into sweetness and its cold nature into warmth. It enters the Liver channel to nourish blood and soothe internal urgency with its sweet, moderating effect. It also warms the Gallbladder, nourishes Heart blood, and tonifies Kidney water.
It is suitable for internal injuries, mental overexertion, emotional stress, essence depletion from excessive sexual activity, and menstrual or pregnancy-related conditions. It nourishes all five organs, harmonizes the blood vessels, moistens skin, nourishes the heart and Chong channel, and calms the spirit. Considered a sacred herb, it is dense and heavy, especially suited to tonify the Kidney.

8. Essential Supplement to the Divine Farmer’s Classic (Ben Jing Feng Yuan)

Prepared Rehmannia Root (Shu Di Huang) is steamed and dried multiple times using fire. It transforms bitterness into sweetness and cold into warmth, representing Yang within Yin. This allows it to tonify the primordial Kidney Qi. Simply boiling it is insufficient; repeated steaming and sun-drying are necessary. Conditions such as sores below the navel, weakness in the thighs, and blurred vision are all rooted in Kidney essence deficiency, which only Prepared Rehmannia Root (Shu Di Huang) can address.

9. Authentic Interpretation of Materia Medica (Ben Cao Qiu Zhen)

Zhang Jing Yue praised Prepared Rehmannia Root (Shu Di Huang) highly. However, he made a rare error when recommending it for cold in the spleen and kidney with vomiting. In such cases, where the internal organs are already cold, warming herbs are more appropriate. Although Prepared Rehmannia Root (Shu Di Huang) is slightly warm, if the cold is severe, it cannot disperse it effectively. It may have some effect in cases of Yin deficiency with excess Yang, or when used alongside warming herbs in external cold, but it should be avoided in true cold conditions with vomiting.

10. Reading the Classic of Materia Medica (Ben Cao Jing Du)

Zhang Jing Yue mistakenly interpreted the therapeutic value of Prepared Rehmannia Root (Shu Di Huang) in the context of all kidney-related diseases, based on the Divine Farmer’s Classic. He regarded it as a primary therapeutic herb rather than a food-grade tonic. Due to its sticky, cloying nature, it may trap pathogenic factors in the Shaoyin region without a proper exit.

11. Correct Meanings of Materia Medica (Ben Cao Zheng Yi)

Rehmannia, in its raw or dried form, has long been recognized as a tonic. In Divine Farmer’s Classic, the term “Qian Di Huang” refers to raw, freshly dug Rehmannia. Later, Prepared Rehmannia Root (Shu Di Huang) was developed through wine steaming and sun-drying to reduce its cold and cloying nature, making it more suitable for those with weak digestion. Its warming transformation enhances its ability to tonify Yin without causing cold-induced diarrhea.
This enables it to nourish the Liver, Spleen, and Kidney and to reach the Lower Burner to enrich fluids and essence. In cases of extreme Yin deficiency, postpartum weakness, or massive blood loss, large and frequent doses can be highly effective. However, for severely deficient individuals with poor appetite and weak spleen Qi, it may cause bloating and digestive disturbance.

12. Pearl Bag of Materia Medica (Zhen Zhu Nang)

A powerful blood tonic that promotes circulation and increases physical strength.

13. Wang Hao Gu

Indicated for patients who are too weak to stand and experience blurred vision.

14. Compendium of Materia Medica (Ben Cao Gang Mu)

Fills the marrow, grows muscle, generates essence and blood, nourishes the five viscera, treats internal injuries, improves hearing and vision, darkens hair, treats male deficiencies and female reproductive disorders, and addresses a hundred postpartum conditions.

15. New Compilation of Materia Medica (Ben Cao Cong Xin)

Nourishes Kidney water, fills the marrow, regulates blood circulation, benefits true Yin, improves hearing and vision, and darkens hair. Also effective for chronic diarrhea, weakness due to overwork, rheumatic pain, Yin deficiency fever, chronic cough with phlegm, shortness of breath, hunger due to stomach deficiency, and postpartum complications. It is the principal herb for nourishing Water in TCM.

 

 

The information provided on this page regarding traditional Chinese medicinal herbs is for educational and informational purposes only. It is not intended as medical advice, diagnosis, or (used in traditional contexts).