Shu Di Huang
StarRehmannia glutinosa (Gaertn.) DC.
☯ TCM Properties
Nourishes Blood; Nourishes Yin; Benefits Essence and Fills the Marrow; Supplements the Liver and Kidneys
Traditional Chinese Uses
Shu Di Huang (prepared rehmannia root) is a warm, sweet herb considered one of the most important Blood and Yin tonics in Chinese medicine. It deeply nourishes Blood and Kidney and Liver Yin, addressing dizziness, blurred vision, tinnitus, irregular menstruation, and pallor from Blood deficiency, as well as lower back weakness, night sweats, and spermatorrhea from Kidney and Liver Yin deficiency. Prepared through repeated steaming, it is richer and more tonic than raw rehmannia and is a foundational ingredient in classical Liver-Kidney deficiency formulas.
Used In Formulas (8)
Botanical Description
Rehmannia glutinosa is a perennial herb of the family Orobanchaceae (formerly Scrophulariaceae), native to clay and sandy soils on slopes and roadsides in northern and central China, where it has long been extensively cultivated. The plant grows 10 to 30 cm tall, with a basal rosette of obovate to oblong, crinkled, softly white-pubescent leaves with crenate margins and prominent veins. In late spring an ascending, glandular-hairy flowering stem bears a few-flowered raceme of nodding, broadly tubular flowers with a five-lobed reddish-purple to yellow-brown corolla, externally pubescent. The medicinal portion is the swollen, fleshy, finger-like tuberous root, harvested in autumn. For Shu Di Huang, the cleaned fresh roots are steamed (traditionally with rice wine) and sun-dried in repeated cycles until they become soft, sticky, lustrous, and black, with a sweet taste.
Active Constituents
Catalpol
Iridoid glycosideConcentration: High in raw root; markedly reduced by steaming/processing to Shu Di (often well below raw levels)
The principal iridoid of Rehmannia and quality marker of the raw drug. Shows hypoglycemic, neuroprotective, anti-inflammatory and renoprotective activity. Because catalpol is heat-labile, its content falls during the repeated steaming that produces prepared Rehmannia, which shifts the herb toward its warm, blood- and yin-tonifying character.
5-Hydroxymethylfurfural (5-HMF)
Furan aldehyde (Maillard product)Concentration: Low in raw root; increases substantially with steaming, a marker of proper processing
Formed from sugars during repeated steaming and sun-drying; its rise is used as an index of correct preparation of Shu Di Huang. Associated with antioxidant activity and the darkened, sweet, warming quality of the processed root.
Acteoside (verbascoside)
Phenylethanoid glycosideConcentration: Minor constituent
A phenylethanoid with strong antioxidant, anti-inflammatory and neuroprotective activity that contributes to the herb's tonic and protective effects.
Rehmannioside A/D
Iridoid glycosidesConcentration: Minor constituents
Iridoid glycosides characteristic of Rehmannia that share the anti-inflammatory and immunomodulatory activity of the iridoid fraction.
Stachyose and oligosaccharides
Oligosaccharides / polysaccharidesConcentration: Major fraction; sugars can exceed 50% of the root
Abundant carbohydrates (stachyose, raffinose, and Rehmannia polysaccharides) that provide immunomodulatory and hematopoietic-supportive activity, underpinning the traditional use for nourishing blood and essence.
Ajugol / aucubin
Iridoid glycosidesConcentration: Minor constituents
Additional iridoids contributing antioxidant and anti-inflammatory activity to the iridoid profile of Rehmannia.
Amino acids (e.g., arginine)
Free amino acidsConcentration: Several percent
Free amino acids that support the nutritive, blood- and essence-tonifying reputation of prepared Rehmannia.
⚠ Drug Interactions
Antidiabetic agents (insulin, sulfonylureas, metformin)
Catalpol and Rehmannia extracts lower blood glucose in animal models, in part via AMPK activation and improved insulin sensitivity, which could add to the effect of glucose-lowering drugs.
Clinical note: Monitor blood glucose when Rehmannia-containing formulas are used alongside antidiabetic therapy; adjust hypoglycemic dosing if needed.
Anticoagulants / antiplatelet agents
Rehmannia has been reported to influence blood coagulation and the blood system in pharmacological reviews; a theoretical additive effect with anticoagulants cannot be excluded.
Clinical note: No documented clinically significant events; routine caution only.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 9-30g | Daily | — | — | — |
Preparation Methods
Prepared Rehmannia by repeated steaming (jiu zheng jiu shai, 'nine steamings and nine sunnings')
Parts: root tuber, yellow rice wine
Raw Rehmannia root is repeatedly steamed (traditionally with yellow wine) and sun-dried until it becomes black, glossy, sweet and sticky. This converts the cold raw root (Sheng Di Huang) into warm Shu Di Huang, reducing catalpol, increasing 5-HMF, and shifting the action toward tonifying blood, yin, essence and marrow. Decocted at 9-30 g.
Charred prepared Rehmannia (Shu Di Tan)
Parts: prepared root slices
Prepared Rehmannia stir-fried until charred on the surface. Charring enhances the astringent, blood-stabilizing action and is used chiefly to stop uterine and other chronic bleeding.
Clinical Studies
The Active Ingredient Catalpol in Rehmannia glutinosa Reduces Blood Glucose in Diabetic Rats via the AMPK Pathway
In diabetic rats, catalpol from Rehmannia glutinosa lowered blood glucose and improved metabolic parameters, with activation of the AMPK signaling pathway identified as a key mechanism, supporting the endocrine/metabolic actions attributed to Rehmannia.
Rehmannia glutinosa: Review of botany, chemistry and pharmacology
Comprehensive review documenting more than 70 compounds (iridoids such as catalpol, saccharides, amino acids and trace elements) and pharmacological actions of Rehmannia on the blood, immune, endocrine, cardiovascular and nervous systems, providing the modern evidence base for its tonic uses.
Historical Texts
Shen Nong Ben Cao Jing (Divine Husbandman's Classic of the Materia Medica)
Han dynasty (c. 200 CE)Xiao Er Yao Zheng Zhi Jue (Craft of Medicinal Treatment for Childhood Disease) by Qian Yi
Song dynasty (1119)Ben Cao Gang Mu (Compendium of Materia Medica) by Li Shizhen
Ming dynasty (1578)References
- Zhang RX, Li MX, Jia ZP. Rehmannia glutinosa: Review of botany, chemistry and pharmacology . Journal of Ethnopharmacology (2008) [DOI]
- Chinese Pharmacopoeia Commission. Rehmanniae Radix Praeparata (Shu Di Huang) monograph . Pharmacopoeia of the People's Republic of China, 2020 Edition, Vol. I (2020) [DOI]
- Bensky D, Clavey S, Stoger E. Chinese Herbal Medicine: Materia Medica, 3rd Edition (Shu Di Huang entry) . Eastland Press, Seattle (2004) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
📝 Notes
Public notes from the community and your own private notes on Shu Di Huang.
No notes yet.