Winter melon peel is a gentle, cooling herb used primarily to help the body release excess water and reduce swelling. It is a common home remedy in East Asia, often brewed as a simple tea during hot summer months to relieve thirst and promote healthy urination. Because it is mild and food-grade, it is well tolerated and frequently combined with other herbs for stronger effect.

'Promotes urination and reduces edema' is the primary action of Dōng Guā Pí. It gently encourages the body to pass more urine, which helps drain excess water and fluid that has accumulated in the tissues. This is the herb's main clinical use: treating swelling (edema) in the face, limbs, or abdomen, along with reduced or difficult urination. Because the herb is mild and non-toxic, it is often used as a gentle supporting herb alongside stronger diuretics like Fú Líng (Poria) or Zhū Líng (Polyporus). In classical theory, plant peels have a special ability to act on the body's surface layer (skin and subcutaneous tissue), making Dōng Guā Pí particularly suited for treating fluid accumulation just beneath the skin.

'Clears Heat and resolves Summer-Heat' refers to the herb's cool nature and its ability to relieve symptoms caused by hot weather, such as intense thirst, scanty dark urine, and general discomfort from the summer heat. It is commonly brewed as a simple tea or combined with watermelon rind (Xī Guā Cuì Yī) for a refreshing summertime drink. This action also extends to clearing mild Heat from the urinary tract, making it useful when urination is both reduced and painful or dark-colored due to Damp-Heat.