Snakegourd Peel Classic Formulas … Natural Herb Library

Primary Actions

Clears heat and transforms phlegm ... Gua Lou Pi is used for cough with thick sputum, chest congestion, and phlegm-heat obstructing the Lung.
Broadens the chest and relieves fullness ... it is especially useful when phlegm binds the chest and causes oppression, discomfort, or painful obstruction.
Reduces swelling and helps early abscess-stage heat toxin ... classical use extends to breast swelling, breast abscess, and related phlegm-heat nodular patterns.

Gua Lou Xie Bai Ban Xia Tang ... chest obstruction with phlegm binding and fullness in the chest.
Qing Qi Hua Tan Wan ... phlegm-heat cough with thick difficult sputum.
Xiao Xian Xiong Tang ... phlegm-heat clumping in the chest and epigastrium.

Later materia medica descriptions place Gua Lou Pi on the chest-opening and phlegm-transforming lane of the Gua Lou family.
Traditional distinctions between peel, seed, and whole fruit emphasize that the peel is narrower, lighter, and more directed to Lung and chest constraint.