The Herb Cabinet 本草

木香 mù xiāng

Aucklandia costus · aucklandia, costus root

Warm Pungent · Bitter SpleenStomachLarge IntestineGallbladder

“The pharmacy's traffic officer. Rich tonic formulas can sit heavy in a weak stomach — a little of this fragrant root keeps everything moving through the intersection.” — Lao Xinglin

What the tradition says

"Wood fragrance" is the pharmacy's great qi mover for the middle: bloating, distension, poor appetite, and griping digestive pain are its home territory^[1]. Its most instructive job, though, is the one it holds in Gui Pi Tang: a small dose amid rich, sweet tonics, there to keep the feast from congealing in a weak digestion — the tradition's habit of building the brake into the engine^[1]. It also regulates a knotted gut in dysenteric disorders, where moving the stuck qi eases the urgency^[1].

What the research says

The root's essential oils (costunolide and friends) show gut-motility and anti-inflammatory signals in laboratory work; clinical evidence is essentially absent. One regulatory note worth knowing: aristolochic-acid scares in the 2000s involved a different plant traded under a similar name (qing mu xiang, an Aristolochia) — proper aucklandia is not an Aristolochia, and reputable suppliers distinguish them strictly.

Where to be careful

Buy from suppliers who label botanically (see above — the one real hazard is substitution, not the herb). The tradition's own limits: warm and drying, so withheld in yin-deficient heat, and dosed small^[1]. CITES lists wild costus; cultivated Chinese stock is the norm.

In the pharmacy

The dense, deeply aromatic root of Aucklandia costus (long traded as Saussurea costus), sliced into tan ovals that scent a whole drawer. Roasted (wei mu xiang) leans toward the intestines; raw toward moving qi broadly^[1].

Reviewed 2026-08-25