Paeonia lactiflora — The Herbarium

Paeonia lactiflora

Bai shao · Chi shao · Chinese peony

Mixed Caution

Part used

root

Native range

Northern China, Mongolia, Siberia and Korea

Morphology

A clump-forming perennial to about a metre with divided leaves and large fragrant white to pink flowers, over thick fleshy roots.

What is in it

monoterpene glycosides paeoniflorin, albiflorin

tannins paeonol

Evidence

The combination formula shakuyaku-kanzo-to, peony with liquorice, has some trial support for muscle cramp including in cirrhosis and in dialysis. The herb alone is little studied.

Safety

Generally well tolerated. The most-studied formula pairs it with liquorice, and carries liquorice’s mineralocorticoid risk — hypertension and potassium loss — rather than peony’s own.

Interactions: In the classical liquorice pairing, all of liquorice’s interactions apply

Regulatory: Permitted as a listed medicine ingredient in Australia.

How the traditions classify it

Galenic European peony, Paeonia officinalis, was classed as hot and dry and used for epilepsy; the plant is named for Paeon, physician to the Greek gods.

Chinese Prepared and peeled as bai shao — bitter, sour and slightly cold, to nourish blood and soften the liver. Unpeeled as chi shao — bitter and slightly cold, to move blood and clear heat. Two medicines from one root, distinguished by processing.

Three systems, rating the same plant. Where they disagree, none of them is correcting the others — they are separate frameworks that arrived at their categories independently.

Historical use

In the Shennong Bencao Jing and among the most frequently prescribed herbs in the materia medica, particularly in gynaecological and pain formulas.

Recorded as history and attributed where possible. Long use establishes that a plant was widely used, not that it worked, and not that it was safe.

Worth knowing

Peony and liquorice together is one of the few Chinese formulas with reasonable Western trial evidence, for muscle cramp — and it carries a hidden hazard that has nothing to do with the peony.

Liquorice at sustained doses causes potassium loss and hypertension. A patient given shakuyaku-kanzo-to for cramp over months is receiving a mineralocorticoid-like drug, and cases of pseudoaldosteronism from exactly this formula are documented in the Japanese literature.

It is a good demonstration that in a formula tradition, the safety profile belongs to the combination and not to the herb you were prescribed it for.

Nomenclature verified against GBIF backbone taxonomy.