Prepared Rehmannia Root

숙지황 (熟地黃) · Rehmannia glutinosa (Gaertn.) DC.

Blood tonic Warm Sweet, slightly bitter Liver, Kidney

NatureWarm

TasteSweet, slightly bitter

MeridiansLiver, Kidney

Part usedRoot, steamed and dried repeatedly (processed form)

FamilyOrobanchaceae

CategoryBlood tonic

Find by concern: Blood deficiency Fatigue Dizziness Menstrual irregularity

Overview

Prepared rehmannia is the richest blood-nourishing root in Korean tradition, made by steaming and drying fresh rehmannia (saeng-jihwang) until it turns from pale to deep black and its nature shifts from cold to warm. The Donguibogam records both forms side by side, distinguishing the cooling, blood-clearing raw root from the warming, deeply tonifying prepared form.

In the Donguibogam

東醫
寶鑑

性溫, 味甘微苦, 無毒. 大補血衰, 善黑鬚髮, 塡骨髓, 長肌肉, 助筋骨, 補虛損, 通血脉, 益氣力, 利耳目.

Source: Donguibogam, Tangaek-pyeon — processed-form note appended to the raw Rehmannia (Saeng-jihwang) entry

TranslationIts nature is warm, its taste sweet and slightly bitter, and it is non-toxic. It greatly tonifies blood deficiency, excels at blackening the hair and beard, fills the bone marrow, builds flesh, strengthens the sinews and bones, tonifies taxation-damage, frees the blood vessels, boosts qi and strength, and benefits the ears and eyes.

Traditional functions

Greatly tonifies the blood
Nourishes liver and kidney yin
Fills essence and marrow
Strengthens sinews and bones

Traditional applications

Blood-deficiency patterns (pallor, dizziness)
Premature graying of hair
Lower-back and knee weakness
Post-illness or postpartum recovery

Traditional preparation

Decoction 8–20g; the core ingredient of Samul-tang and Yukmi-jihwang-hwan.

Cautions

Caution: Rich and cloying in nature; traditionally used cautiously with digestive weakness, phlegm-damp, or bloating, since its dense, nourishing quality can burden the stomach. Often combined with tangerine peel to offset this. Consult a professional before use.

Frequently asked questions

What is the difference between raw and prepared rehmannia?

The Donguibogam distinguishes them clearly: raw rehmannia (saeng-jihwang) is cold in nature and clears heat from the blood, while prepared rehmannia (suk-jihwang), made by repeated steaming and drying, becomes warm and is used for deep, rich blood and essence tonification.

Why is it often combined with tangerine peel?

Prepared rehmannia's rich, dense quality can be heavy on digestion; tangerine peel's qi-regulating action is traditionally added to offset this and keep the stomach comfortable.

Sources

동의보감 탕액편 (원문) — 한문 원문 발췌 — 한의학고전DB 탕액편 대조 검증 완료 (DATA-001)
한의학고전DB (mediclassics.kr) — 국역 참조 후 자체 재서술 (LEGAL-001)

DonguiHub is an educational and informational platform about the history and tradition of Korean medicine. It does not provide medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional about health conditions and before using any herb.