The Herb Cabinet 本草

泽泻 zé xiè

Alisma orientale · water plantain rhizome

Cold Sweet · Bland KidneyBladder

“The marsh plant that teaches water where to go. Every rich tonic formula needs a drain — this is the one Liu Wei Di Huang Wan trusts.” — Lao Xinglin

What the tradition says

A marsh plant for marsh problems: ze xie promotes urination and drains dampness, with a cold edge that also clears the murky heat dampness breeds — difficult or burning urination, edema, damp-heat below^[1]. Its most instructive job is in Liu Wei Di Huang Wan: as rehmannia floods the kidney with rich yin, ze xie flushes the turbidity such richness creates — the tradition's three-fill-three-drain architecture depending on a drain this reliable^[1]. It also appears wherever phlegm-fluids collect: the classic pair with bai zhu treats dizziness from fluids misting upward.

What the research says

Alisma triterpenes are studied for diuretic and lipid-lowering signals in animal models; human evidence is thin and mostly formula-bound. One real note from the pharmacovigilance literature: very high, prolonged doses have raised concern in animal studies — another argument for formula doses over supplement enthusiasm.

Where to be careful

A cold drainer is wrong for the depleted-and-dry: the tradition withholds it where yin deficiency shows without dampness, and in leaking-essence patterns^[1]. Not an herb for daily solo use.

In the pharmacy

Cream-white, dense rounds of Alisma orientale rhizome. Salt-fried ze xie aims the drain more squarely at the kidney^[1].

Reviewed 2026-08-26