A double-blind, randomised, placebo-controlled study to evaluate the safety and efficacy of Sambucol liquid formulation to reduce the duration and severity of the common cold and flu symptoms in adults.

Treatment is an orally dosed liquid-form supplement containing a standardised elderberry extract (Sambucol). The dose is 15mL, taken 4 times daily, commenced within the first 24 hours of onset of symptoms of cold/flu and continued until complete resolution of symptoms. Once a person has experienced a cold/flu episode their participation in the trial is completed. Active ingredient: Sambucus nigra (Black Elderberry) extract equivalent to fruit juice 5.7g/15ml liquid. All participants are provided with the cold/flu treatment pack which includes the product (active treatment or placebo), a daily symptom diary, a thermometer and a pre-prepared QML pathology form for Influenza antigen testing. If a participant experiences 3 or more cold/flu symptoms during the study period (according to the Wisconsin Upper Respiratory Symptom Survey), they need to a) start treatment, b) record their symptom severity and duration in the diary every day until symptoms resolved c) take temperature daily d) if temperature >38 degrees C have the antigen test taken at a local QML pathology collection centre. During the treatment period, a clinical trial nurse/investigator will make contact with each participant, at least every 2 days to ensure symptoms are not such that they require medical intervention/hospitalisation. If fever persists for greater than 3 days or if other symptoms worsen over a 5 day period then the participant will be referred to the referring medical consultant. Within 2 weeks from the cold/flu resolving, the participant is asked to attend a final interview, returning the diary and unused product which will be used to monitor adherence. Once the number of cold/flu episodes reaches the quota (120 cold and 80 flu episodes), all participants will be informed that the study has been completed. Therefore, it is expected that not all participants will experience a cold/flu episode while enrolled in the study.