Evidence Level
Moderate
Andrographis has an unusually strong evidence base for a herbal remedy. The Cochrane review by Hu et al. (2017) analyzed 33 RCTs with 7,175 participants, concluding that andrographis (alone or in combination) was superior to placebo for relieving cold symptoms. The standardized extract Kan Jang has been tested in multiple double-blind RCTs conducted in Sweden and other countries, showing consistent reductions in sore throat, nasal symptoms, and cough. Coon and Ernst (2004) conducted an earlier systematic review reaching similar conclusions. Andrographolide's anti-inflammatory mechanism via NF-kB inhibition is well-characterized and provides a pharmacological basis for its clinical effects.