Shao Yao Gan Cao Tang — Peony and Licorice Decoction

On this page

1. Overview
2. TCM pattern
3. Key herbs
4. Conditions treated
5. Cautions

Overview

Shao Yao Gan Cao Tang — Peony and Licorice Decoction — is one of the simplest and most elegant formulas in the entire Chinese herbal medicine tradition, composed of just two herbs yet remarkably effective for its specific indication. Originating from Zhang Zhongjing’s Shang Han Lun, it is the primary formula for muscle spasm and cramping pain arising from Yin and Blood deficiency failing to nourish and moisten the sinews and muscles. The formula works by nourishing Yin and Blood (through Bai Shao) and simultaneously moderating and relaxing the sinews (through Gan Cao), making it one of the most targeted antispasmodic formulas in TCM.

TCM pattern

Prescribed for Yin and Blood deficiency with spasming of the sinews and muscles, characterised by: acute or chronic muscle cramps and spasms (particularly of the calf muscles at night), abdominal cramping and spasmodic pain, dry skin and muscles, a pale tongue, and a thin, wiry pulse. The mechanism is straightforward: when Yin and Blood are insufficient, the sinews and muscles lose their nourishment and become prone to spasmodic contraction.

Key herbs

1. Bai Shao (Paeonia lactiflora root) — the principal herb (used in a large dose); nourishes Blood and Yin, softens the Liver and directly relaxes spasm in the sinews and muscles; alleviates pain
2. Zhi Gan Cao (honey-fried Glycyrrhiza root) — tonifies Qi and the Middle Jiao, moderates urgency and spasm, and works synergistically with Bai Shao to relax the sinews; the classic herb pairing for antispasmodic effect in TCM

Conditions treated

1. Nocturnal leg cramps — the formula’s most frequent modern application; highly effective for night-time calf cramps from Yin and Blood deficiency
2. Muscle spasms and cramps anywhere in the body from Yin and Blood deficiency
3. Abdominal cramping and IBS pain — often combined with other IBS formulas for its antispasmodic action
4. Dysmenorrhoea (menstrual cramps) — used as part of complex formulas for painful periods
5. Restless legs syndrome from Blood deficiency failing to nourish the lower limb sinews
6. Tension headaches with neck and shoulder muscle spasm from Blood and Yin deficiency
7. Writer’s cramp and hand spasm from Yin and Blood deficiency in the sinews

Cautions

Always consult a qualified Chinese herbalist registered with the Register of Chinese Herbal Medicine (RCHM). Online herbal consultations are available. See the prices page for costs.