Two randomized double-blind, placebo-controlled parallel group clinical trials were performed to investigate the effect of a standardized extract (SHA-10) of Andrographis paniculata fixed combination (Kan jang) in the treatment of uncomplicated upper-respiratory tract infections. 46 patients in the pilot study and 179 patients in the phase III study completed the study according to the protocol. Medication was taken three times daily for a minimum of 3 days and a maximum of 8 days for the pilot study, and for exactly three days in the phase III study. The primary outcome measures in the patients self-evaluation were: related to pain in the muscle, cough, throat symptoms, headache, nasal symptoms and eye symptoms and temperature. The physician's fixed score diagnosis was based mainly on sign/symptoms: ears, nose, oral cavity, lymph glands-tonsils and eyes. The total symptom score showed a tendency toward improvement in the pilot study (p = 0,08), while both the total symptom score and total diagnosis score showed highly significant improvement (p < or = 0.0006 resp. 0.003) in the verum group as compared with the placebo. In both studies throat symptoms/signs, were found to show the most significant improvement.