Andrographis paniculata is a medicinal plant traditionally used in Asian countries for a range of illnesses, especially infections and fever. In recent decades, it has been the subject of clinical and preclinical research for its potential antiviral and immunomodulatory effects.

Several randomized controlled trials and systematic reviews have evaluated Andrographis (often as an extract standardized for andrographolide content) for the treatment of upper respiratory tract infections, including the common cold and influenza-like illnesses. A 2017 Cochrane review found that Andrographis preparations may reduce the severity and duration of symptoms such as cough and sore throat compared to placebo, though most studies were small and of variable quality. The proposed mechanisms include inhibition of viral replication and modulation of immune responses, as observed in both in vitro and animal studies. There is also some evidence of anti-inflammatory effects that may contribute to symptom relief during viral infections.

However, evidence is strongest for mild, self-limiting viral infections (e.g., common cold), and there is insufficient evidence for use in severe viral illnesses. Most studies focus on short-term use and report few adverse effects, but high-quality, large-scale trials are still lacking. Thus, while the scientific evidence is moderate (rating 3/5), more research is needed to clarify its efficacy and safety for broader viral infection indications.