Prepared Rehmannia

熟地黄 · Shú Dì Huáng

Builds blood and rebuilds deep reserves

Properties

WarmingWarming botanicalSweet

Concerns

What it does

Prepared rehmannia rebuilds blood and supports kidney essence: postpartum exhaustion, irregular periods, infertility, hot flashes, weak knees, premature graying. In TCM, it nourishes both yin and blood. It's a key herb in formulas like Liù Wèi Dì Huáng Wán and Sì Wù Tāng. One systematic review covers blood-building effects.

How to take it

Drink

Decoct 9–30g of prepared rehmannia in water for 30 minutes. Drink 1 cup, 1–2x daily as a long-term tonic. Common in Liu Wei Di Huang Wan formula.

Try a Liu Wei Di Huang Wan formula for chronic kidney-essence depletion

Safety

Generally well tolerated as a long-term tonic
Heavy and rich. Pair with digestive herbs if you have weak digestion
Skip with chronic diarrhea or stuck phlegm
May interact with diabetes medications
Talk to your doctor before starting, especially if you take medication

Formulas it's in

Four Substances

四物湯 · sì wù tāng

The foundational TCM formula for nourishing blood. Often called the women's tonic.

Six-Ingredient Rehmannia

六味地黃丸 · liù wèi dì huáng wán

Probably the most-prescribed TCM formula in the world. The classical Kidney yin tonic.

Where it comes from

Rehmannia (Rehmannia glutinosa) yields two distinct TCM herbs from one plant: the raw root (Shēng Dì Huáng) for blood-heat and bleeding, and the processed root (Shú Dì Huáng) covered here for blood-building. Processing involves repeated steaming with rice wine, transforming the root from cooling to slightly warming. Prepared rehmannia is the most-used blood-tonic in modern TCM.