What it is:
This herb is the root of Paeonia lactiflora Pall.(family Ranunculaceae)which is chiefly produced in Zhejiang, Anhui and Sichuan provinces and all white peony is cultivated. The root is dug in summer or autumn and washed clean. After removal of the lateral roots and skin, it is boiled for a short while and then dried in the sun, sliced and used unprepared, stir-baked or stir-baked with wine.

Property:
Bitter and sour in flavour, slightly cold in property, acting on the liver and spleen channels.

Effects:
Nourishing the blood, regulating menstru- ation, reinforcing yin with astringent action to stop sweating,nourishing the liver pain and suppressing the liver-yang.

Used for:
1. Irregular menstruation, dysmenorrhea, metrorrhagia and metrostaxis due to blood deficiency. It is often used along with Chinese angelica root , chuanxiong rhizome, prepared rehmannia root, etc., as in Decoction of Four Ingredients ( Siwu Tang).

2. Spontaneous sweating due to exterior deficiency and night sweat due to yin deficiency. For the former, it is often used with cinnamon twig; for the latter, it is often prescribed with oyster shell, dragon's bone , arborvitae seed, etc.

3. Pain in the hypochondrium, stomach and abdomen due to disorder of the liver- qi, or spasm and pain in the extremities. For pain in the hypochondrium due to stagnation of the liver-qi, it is often dispensed with bupleurum root and cyperus tuber, as in Bupleurum Powder for Dispersing Liver-qi (Chaihu Shugan San); for abdominal pain and diarrhea, it can be used with white atractylodes rhizome, tangerine peel and ledebouriella root, as in Prescription of Importance for Diarrhea with Pain(Tongxie Yaofang) ; for dysenteric abdominal pain, it can be used with aucklandia root , areca seed and coptis root ; for spasmodic pain of the stomach and abdomen or in the extremities, it is often used with liquorice as in Decoction of Peony and liquorice(Shaoyao Gancao Tang).

4. For hyperac-tivity of the liver- yang marked by headache and vertigo, it is often used along with dried rehmannia root , achyranthes root and red ochre, as in Sweeping Down Decoction for Hyper-tension(Jianling Tang).

Dosage and admi-nistration: 5- 10g, or 15-30g in large dosage, decocted in water for an oral dose. For inducing astringency to rein-force yin, calming the liver and treating dysentery, it is usually used unprepared; for nou-rishing the liver to relieve pain, it is usually used stir-baked; it is made less cold after stir- baking with wine.

Precautions:
The herb should not be used alone in cases of yang exhaustion with cold manifesta-tions of deficiency type. It is incompa-tible with black hellebore( Radix Veratri).