Zhi Zi Pi (Gardenia Peel)

The official drug is Zhi Zi, the dried ripe fruit of Gardenia jasminoides. The pharmacopoeial name is Gardeniae Fructus. Zhi Zi Pi is the pericarp after the seeds are removed; Zhi Zi Ren is the seed. Classics: the peel reaches the exterior and clears heat in the skin, flesh and Lung-defense; the seed enters the interior and clears internal heat. Modern clinics often use the whole fruit; chemically the seed is richer in geniposide. Jiao Zhi Zi is the scorch-fried whole fruit, leaning toward cooling Blood to stop bleeding. If the prescription writes Zhi Zi Pi, distinguish it from whole fruit and seed. Ornamental gardenia petals are not this drug.

Flavor, nature and channels match Zhi Zi: bitter and cold, entering the Heart, Lung and Triple Burner. Tradition emphasizes clearing the qi aspect, reaching the skin surface, and draining constrained heat of the Lung-defense and Triple Burner; it can also clear heat, disinhibit damp, cool Blood and resolve toxin. It is used for feverish skin, flushed face, Lung heat and heat-disease vexation that leans exterior. Bitter-cold and downbearing, it does not suit Spleen-Stomach deficient cold, loose stool or Stomach-cold pain.

Skin, Lung-defense, flushed face and red eyes leaning exterior heat may use Zhi Zi Pi. Vexation, jaundice, strangury and interior heat more often use whole Zhi Zi or Zhi Zi Ren. Blood-heat bleeding uses Jiao Zhi Zi. External sprain more often uses raw whole fruit powdered. If the pharmacy does not separate peel and seed, whole Zhi Zi is usually substituted—note this on the prescription.