Andrographis paniculata has been traditionally used in Asian medicine, particularly in Ayurveda and Traditional Chinese Medicine, for the treatment and prevention of upper respiratory tract infections, including the common cold. In recent decades, its use has been evaluated in scientific studies. Several randomized, double-blind, placebo-controlled clinical trials and meta-analyses have investigated its efficacy for preventing or treating colds.

Systematic reviews, such as those published in the journal Phytomedicine (2017) and the Cochrane Database of Systematic Reviews (2017), have found that Andrographis extracts (typically standardized for the active compound andrographolide) can significantly reduce the severity and duration of cold symptoms when compared to placebo. Some studies have also indicated that it may reduce the incidence of respiratory tract infections, suggesting a potential preventive benefit, although most evidence pertains to treatment rather than prevention. The herb is thought to exert immunomodulatory and anti-inflammatory effects, which may underlie these observed benefits.

The overall quality of evidence is moderate, with some limitations regarding study heterogeneity and sample sizes. However, the consistency of positive results across multiple trials supports its use as an adjunct for the prevention or symptomatic treatment of colds. The safety profile appears favorable in short-term use. Therefore, there is both a traditional basis and scientific validation for the use of Andrographis paniculata in this context, with scientific evidence being the stronger justification.