Piper chaba, also known as chui jhal or piper longum, has a long history of use in traditional medicine systems of South and Southeast Asia, particularly in Ayurveda and traditional Thai medicine. It has been employed for various respiratory ailments, including dry cough, bronchitis, and throat irritation. The dried fruit or roots are commonly used in herbal preparations, often as part of polyherbal remedies.

Traditional practitioners believe that Piper chaba possesses expectorant and demulcent properties, which help relieve throat irritation and suppress dry cough. It is sometimes combined with honey or other herbs to enhance its soothing effects. However, the scientific evidence supporting its efficacy for dry cough is limited. Some laboratory studies have indicated that related species like Piper longum may possess antitussive (cough-suppressing) activity, but direct clinical studies on Piper chaba for dry cough are lacking.

In summary, the use of Piper chaba for dry cough is primarily justified by traditional knowledge and historical usage. While there is some ethnobotanical and preclinical support, high-quality clinical trials or robust pharmacological evidence are not yet available to firmly validate its effectiveness for this condition.