Rehmanniae Radix Praeparata
Aliases：Shudi、Dashudi、Shashudi
Shudihuang (Rehmanniae Radix Preparata) is a Chinese medicinal herb that tonifies deficiency. It was first recorded in Bencao Shiyi (Supplement to the Materia Medica). It is the dried tuberous root of Rehmannia glutinosa Libosch. (family Scrophulariaceae) after being processed (steamed and dried). It is mainly produced in Henan, Liaoning, Hebei, Shandong, and Zhejiang provinces.
Efficacy & Actions
It has the actions of tonifying blood and nourishing Yin, as well as supplementing essence and filling the marrow.
Indications
1. Blood deficiency pattern Shudihuang is indicated for conditions caused by blood deficiency, such as sallow complexion, dizziness, palpitations, menstrual irregularities, and metrorrhagia with bleeding. 2. Liver‑kidney yin deficiency pattern Shudihuang is indicated for conditions caused by deficiency of liver and kidney yin, including soreness and weakness of the lower back and knees, bone‑steaming tidal fever, night sweats, spermatorrhea, internal heat‑related wasting thirst disorder (Xiaoke), dizziness and tinnitus, and premature graying of hair and beard.
Modern Pharmacology
Shudihuang has the effects of promoting hematopoiesis, lowering blood glucose, enhancing memory, and enhancing immunity, among others.
Ingredients
Shudihuang mainly contains phenylethanoid glycosides (such as verbascoside, etc.), as well as monosaccharides, various amino acids, and other components.
Usage & Dosage
Decoction: 9–15 g; or used in pills or powders; or prepared as an extract (ointment) or steeped in wine.
Contraindications
Shudihuang is moist and cloying in nature and may impair digestion. Therefore, it should be used with caution in cases of Spleen and Stomach deficiency, abdominal fullness with loose stools, as well as Qi stagnation with profuse phlegm.
Selected Formulas
1. Shudihuang with Shanzhuyu (Cornus fruit) Shudihuang excels at nourishing the liver and kidney, enriching blood, and replenishing essence. Shanzhuyu is good at warming and tonifying the liver and kidney, reducing frequent urination, and stabilizing essence. Their combination significantly enhances the effects of nourishing kidney yin, consolidating essence, and stopping night sweats. Indicated for dizziness, tinnitus, deafness, soreness and weakness of the lower back and knees, impotence and spermatorrhea, and night sweats due to liver‑kidney yin deficiency. 2. Shudihuang with Shanyao (Chinese yam) Shudihuang specializes in enriching blood, nourishing yin, and replenishing essence and marrow. Shanyao is adept at benefiting the kidney, consolidating essence, supplementing the spleen, and nourishing yin. The pair strengthens the action of enriching kidney yin, consolidating essence, and stopping spermatorrhea. Indicated for spermatorrhea and enuresis (bedwetting) due to kidney deficiency. 3. Shudihuang with Baishao (White peony root) Shudihuang is strong in enriching blood, nourishing yin, and replenishing essence and marrow. Baishao is good at nourishing blood, astringing yin, softening the liver, and alleviating pain. Their combination enhances the effects of enriching kidney yin, tonifying blood, and nourishing blood. Indicated for menstrual irregularities, blurred vision, and poor eyesight due to liver blood deficiency and liver‑kidney insufficiency. 4. Shudihuang with Xixin (Asarum root) Shudihuang excels at enriching blood and nourishing yin. Xixin is good at dispelling wind and cold. Combined, they enhance the action of tonifying the kidney and dispersing cold. Indicated for low back pain due to kidney deficiency. 5. Shudihuang with Sangjisheng (Taxillus herb) Shudihuang is good at enriching blood, nourishing yin, and replenishing essence and marrow. Sangjisheng is good at benefiting the liver and kidney, nourishing blood, and calming the fetus. The combination enhances the effects of tonifying the kidney, replenishing essence, nourishing blood, and stabilizing the fetus. Indicated for threatened miscarriage (fetal irritability) due to deficiency of liver‑kidney essence and blood. 6. Shudihuang with Wuweizi (Schisandra fruit) Shudihuang excels at replenishing kidney essence. Wuweizi is good at astringing the lung, nourishing the kidney, and stopping cough. Together, they strengthen the actions of tonifying the kidney, receiving qi (helping the kidney hold qi), astringing the lung, and stopping cough. Indicated for cough and wheezing, and difficulty in holding qi (shortness of breath with prolonged exhalation) due to deficiency of both lung and kidney.
Daily Consumption
Tea: 6–12g sliced, steep in boiling water for 10–15 min. May add goji berries or red dates. Soup: 10–15g, simmer with pork ribs, chicken, or lamb for 1–2 h. Often combined with Angelica, Astragalus, goji. Congee: 6–10g, decoct and use liquid to cook rice porridge. Wine infusion: 30g, soak in liquor with Angelica and goji for 15–30 days. Take 10–15ml daily. Precautions: Daily dietary dose: 6–15g. Avoid in cases of spleen-stomach deficiency, qi stagnation with profuse phlegm, abdominal distension, loose stools. Do not eat with radish, scallion, or Chinese onion. Use with caution during pregnancy; consult a TCM practitioner.
Medicinal Parts
dried tuberous root
Selection & Storage
Store in a dry container. For various processed products of Shudihuang (prepared Rehmannia root), keep in airtight containers in a cool, dry place, protected from mold and insects. For Shudihuang Charcoal, spread out to cool and dissipate heat to prevent re-ignition.