Honey loquat syrup, also known as "pei pa koa," is primarily used in traditional Chinese medicine (TCM) to support respiratory health, including the prevention and relief of symptoms associated with colds, such as cough and sore throat. Its formulation typically includes loquat leaf (Eriobotrya japonica), honey, and various other herbs. Historically, TCM practitioners have recommended it for its soothing and demulcent effects on the throat and its purported ability to "moisten the lungs" and reduce phlegm.

Scientific validation for its effectiveness in cold prevention is limited. While honey itself has mild antimicrobial properties and is recognized for soothing throat irritation, and loquat leaves have demonstrated some anti-inflammatory and antioxidant effects in laboratory studies, robust clinical trials in humans specifically assessing honey loquat syrup for cold prevention are lacking. Most evidence remains anecdotal or based on traditional use rather than rigorous scientific testing.

In summary, honey loquat syrup is justified for use in cold prevention primarily by tradition, with limited scientific backing. Its safety profile is generally favorable, but its true efficacy for this condition remains to be clearly established in controlled clinical studies.