Methods This randomised placebo-controlled trial involved subjects aged between 18 and 65 who were randomly assigned to either RCM-102 or a placebo group. After a two-week baseline period, all subjects took either RCM-102 or placebo capsules (two capsules each time, three times daily with a four hour interval) for a period of eight weeks. The primary end-points were the Five-Point Scale symptom scores. Rhinoconjunctivitis Quality of Life Questionnaire, relief medication usage, adverse events, kidney and liver function tests and full blood examination were secondary end-points. Intention-to-treat analysis was applied.